Printer Friendly

Mineralogy of the Saint-Amabile Sill.

An extensive nepheline syenite sill, genetically related to Mont Saint-Hilaire and other intrusions in the Monteregian alkaline rock province, is a recently discovered, prolific locality for many rare minerals. More than 100 species have been identified to date, including ancylite-(La), calciohilairite, cordylite-(Ce), franconite, gaidonnayite, hilairite, hochelagaite, kukharenkoite-(Ce), magadiite, sazhinite-(Ce), serandite, shkatulkalite, thornasite, tuperssuatsiaite, yofortierite, zakharovite, and the new species, varennesite. Most of the minerals occur as well-formed microcrystals.

LOCATION

The Saint-Amable sill is located between the towns of Varennes and Saint-Amable in Vercheres County, Quebec, approximately 20 km east-northeast of Montreal and 7 km east of the Saint Lawrence River (latitude: 45 [degrees] 39 [minutes] N; longitude: 73 [degrees] 17 [minutes] W; Canada National Topographic System, Map 31 H/11, Beloeil). It forms part of an extensive low plateau or butte which rises an average of 25 meters above the surrounding, generally flat countryside. The butte comprises an oblong area of approximately 100 [km.sup.2], and is situated within the town boundaries of Varennes, Saint-Amable and Sainte-Julie, with the town of Saint-Amable near its center. Approximately 60% of the butte is covered by woodland, 30% by farmland and 10% by mixed residential and commercial properties.

The Demix-Varennes quarry (the main mineral collecting site) and three small, Bau-Val quarries are located at the northwestern edge of the butte, approximately 3.5 km west-northwest from the center of the town of St-Amable, and 6 km east-southeast from the town of Varennes on the south shore of the Saint Lawrence River. At its current state of development, approximately 60% of the Demix-Varennes quarry lies within the municipal limits of Varennes, and 40% within the municipal limits of Saint-Amable.

Access to the Demix-Varennes and Bau-Val quarries is from Autoroute 30 at Exit 136, approximately 10 km north (in the direction of Sorel) of the Autoroute 20 (Trans-Canada Highway) interchange. Take Exit 136 to Chemin de la Butte-aux-Renards, proceed east on this road for 1.7 km, then turn right (SE) onto a paved road 1.9 km long, which ends at the Demix-Varennes quarry gate; a private, unpaved road to the right leads to the Bau-Val quarries.

HISTORY

The earliest mention of the Saint-Amable sill is in a report of a survey of the regional geology carried out mainly during 1942 (Clark, 1943 and 1955). Clark, who named the sill after the town of Saint-Amable, provided the locations and brief descriptions of the sill outcrops visible at that time. The first known quarry to exploit the hard nepheline syenite sill rock was opened in 1959 by Carrieres Varennes Ltee, at the northwestern edge of the butte, within the town limits of Varennes. The primary use of the crushed rock was, and still is, as concrete aggregate and road ballast. The quarry ownership changed to Carrieres Goyer Ltee. in the period 1969-73, and during this time the quarry was largely inactive. In 1973 the quarry and a large tract of land surrounding it were acquired by Demix Inc. (now Demix Agregats, a division of Ciment Saint-Laurent), and a new crushing plant was installed. The quarry was reactivated and has been in continuous production ever since. This is the same company which operated the now-famous Demix quarry at Mont Saint-Hilaire until 1981 (Horvath and Gault, 1990).

A second company, Les Carrieres St-Amable Ltee., commenced operations immediately to the south of the Carrieres Varennes quarry in 1964. Two quarry pits, now designated as Bau-Val Nos. 1 and 2, were developed and worked for a few years. By 1972 both of these were inactive and water-filled. The property was acquired by Bau-Val Inc. (now Pavage Varennes, a division of Bau-Val) from Les Carrieres St-Amable Ltee. around 1970. A new pit, Bau-Val No. 3, was started in the 1980's northwest of the two older pits; this and the dewatered Bau-Val No. 2 have been worked intermittently in recent years by Sintra Inc. under a lease from Pavage Varennes. The Bau-Val No. 1 and No. 2 pit designations were used by Globensky (1985); the third pit was arbitrarily designated as Bau-Val No. 3 by the authors. The three Bau-Val pits are separated from the Demix-Varennes quarry by a narrow, blast-fractured wall of rock.

During the last few years the Demix-Varennes quarry has been worked mainly at the Saint-Amable end, with current and planned future expansion continuing toward the southeast and northeast. Quarrying is confined to the sill, as there is no market for the underlying soft shale. This has resulted in a very large (approximately 1.5 x 0.9 km) but shallow (10-15 meters deep) open pit.

Although Clark (1955) observed vesicles in one of the sill outcrops, he made no mention of any minerals. During a visit in 1962 to what is now the Demix-Varennes quarry, one of the authors (PT) noted the presence of mineralized cavities containing unusual minerals. Among the species identified from the material collected there were rhodochrosite, mangan-neptunite, natrolite, aegirine, serandite, eudialyte and astrophyllite. However, there was very little additional collecting activity during the next ten years as local mineral collectors focussed their attention on Mont Saint-Hilaire. In 1972, two of the authors (EP-H and LH) began collecting in the present Demix-Varennes quarry, which was inactive at the time, and have continued to make infrequent visits over the following 19 years during which a number of additional minerals were identified, including the rare species yofortierite, doyleite and catapleiite. A comprehensive study of the mineralogy of the Saint-Amable sill was initiated by the authors in 1991, and entailed the examination of a large volume of material collected over many years up to the present. The list of species quickly grew to the current, rather impressive total of over 100, and includes the new sodium-manganese silicate, varennesite (Grice and Gault, 1995), which is named after the locality, the Demix-Varennes quarry. Several other possible new species are under study, and the potential for the discovery of additional species is very good.

This paper summarizes the results of our investigations as of December 1997.

GEOLOGY

The Saint-Amable sill is genetically related to the Monteregian alkaline rock province of Lower Cretaceous age (Adams, 1903). The province includes ten main plutons known as the Monteregian Hills, which are aligned along an east-west-trending belt, from Mont Megantic about 190 km east of Montreal, to Oka 35 km west of Montreal. Several magnetic anomalies associated with the belt are believed to represent additional, buried plutons (Philpotts, 1970; Telford et al., 1976). There are also numerous minor intrusions in the form of dikes, sills and igneous breccias (Clark, 1972; Currie, 1976; Globensky, 1985). Besides the Saint-Amable sill, a number of other major sills have been exposed in and around the greater Montreal area by quarrying and building excavations. One of these, the Saint-Michel sill (Francon quarry), has become a famous mineral collecting site (Sabina, 1978; Vard and Williams-Jones, 1993) and the type locality for nine mineral species.

The Saint-Amable sill is the most extensive and the thickest known Monteregian sill (Hodgson, 1969). While it has not been age-dated, it is very likely coeval with two of the closest Monteregian intrusives, Mont Saint-Bruno and Mont Saint-Hilaire, dated at 90 and 135 [+ or -] 10 million years respectively (Gold, 1979; Eby, 1984). As noted previously, the sill underlies a butte, which probably formed as a result of the resistance of the sill rock to glacial abrasion and other erosion. The sill extends below a thin overburden of glacial till for a distance of at least 3 km from the northwestern margin of the butte, and occupies an area of at least 8 to 9 [km.sup.2] based on known surface outcrops, quarrying and related surface stripping and test drilling. It is probable that the sill has a considerably larger total area, but the scarcity of outcrops and dense forest cover has thus far precluded full mapping.

The sill overlies black shale of the Lorraine Group of Upper Ordovician age (425-450 million years), interbedded with thin layers of sandstone and limestone (Clark, 1955; Globensky, 1985). Its upper surface is an erosional surface, and only its lower contact can be seen. In the Demix-Varennes quarry, the sill has an average dip of 3[degrees] NE (Globensky, 1985) and becomes generally thicker toward the east. The thickness varies from about 3 meters to a maximum of 24 meters (Globensky, 1985). Since its present upper surface is erosional, it is certain that the sill was thicker at the time of emplacement. This interpretation is supported by the fact that horizontal-trending, cavity-rich mineralized zones in the upper portion of the sill are absent where the sill thickness is reduced. The lower contact of the sill is undulating, probably due to natural stoping of the soft, fissile shale. There is no visible evidence of hornfelsization of the shale at the sill contact. In one unusual occurrence a xenolith of hornfelsized shale was observed in situ, in the sill near the contact; the xenolith, about 1 meter across, was brecciated throughout and permeated by a dense network of narrow fissures lined with labuntsovite and pyrrhotite crystals.

A conspicuous feature of the sill is a well-defined contact zone which is much lighter in color than the rest of the sill. The zone follows the undulations of the lower contact and is up to 2.5 meters thick. Rock in this zone has a peculiar mottled appearance and contains numerous randomly oriented, mineralized cavities. A body of very similar rock exposed in the south corner of the Demix-Varennes quarry in 1994-95 appeared to occupy the entire thickness of the sill; the rock was in part shattered and heavily weathered, and its margins were obscured. Its relationship to the rest of the sill is unclear.

Based on an examination of sill outcrops, one of which exposed a 12-meter-thick section, Clark (1955) concluded that the sill was made up of multiple injections, each 0.6 to 1.2 meters thick, and "each with an approach to a chill zone." No detailed study has been made of the internal structure of the sill as exposed in the present quarries. Globensky (1985) cited Clark's conclusions but added no new information regarding the structure or mechanism of sill emplacement. Our examination of the sill has not revealed any evidence of multiple emplacements. The most notable internal features of the sill are horizontal-trending zones of mineralized cavities in the upper portions of the sill, close to the erosional surface, and thin, mainly horizontal mineralized seams containing tiny cavities that often extend to the central portions of the sill. The location of these mineralized zones was probably controlled by converging solidification fronts within a single thick emplacement of magma (Marsh, 1996).

A peculiar feature of the sill is the rare occurrence in the Demix-Varennes quarry of pod-like, cavity-rich areas which appear to have a hydrothermal origin. These are also found in the upper zones of the sill, and have a distinctive mineralogy.

Several smaller (20-50 cm thick) sills and dikes occur below the main sill, and are exposed in the Demix-Varennes and Bau-Val quarries. The dikes truncate at the main sill contact. The rocks forming these subsidiary sills and dikes appear to be considerably different from that of the main sill, and surely represent separate injections.

Regional stresses have resulted in prominent vertical jointing in the sill rock. One set has a strike of N10 [degrees] W and a spacing of 30 cm or more, and a second set has a strike of N65 [degrees] W with a spacing of 2 cm or more (Globensky, 1985).

The source of the magma which formed the sill is a matter of conjecture. The nearest Monteregian pluton, Mont Saint-Bruno, is approximately 10 km south of the sill exposures, whereas Mont Saint-Hilaire is approximately 15 km to the southeast. A ridge-like projection of the butte which contains the sill extends to about 1 km from Mont Saint-Bruno. Dresser (1910), in his report on the geology of Mont Saint-Bruno, suggested that this ridge might conceal an "underlying sill or trap" connected to the pluton. Closer to the Saint-Amable sill there is a magnetic anomaly which has been interpreted as a large, deeply buried Monteregian pluton (Telford et al., 1976). It is centered approximately 3 km west of the western edge of the sill, and extends below it at an estimated minimum depth of over 900 meters. It is interesting to speculate whether this may be the actual "feeder stock" for the Saint-Amable sill.

PETROLOGY and GEOCHEMISTRY

The bulk of the sill is a dense, gray to dark gray, fine-grained rock with relatively little textural variation. The average grain-size is 40 [[micro]meter] (Grice and Gault, 1995). The rock has been variously [TABULAR DATA FOR TABLE 1 OMITTED] described as tinguaite (Clark, 1955; Hodgson, 1969), trachytic phonolite (Hanes, 1962) and nepheline syenite (Currie, 1976; Globensky, 1985). Compositionally, the rock types covered by these terms are similar. According to current classification schemes (Sorensen, 1974; Le Maitre, 1976) and the available petrographic and chemical analyses, the sill rock is best classified as nepheline syenite.

Only limited studies of the petrography of the sill have been carried out. Hanes (1962) and Hodgson (1969) examined a small number of rock samples taken during the initial period of quarrying. Their modal analyses of thin sections showed the principal rock-forming minerals to be: K-feldspar, 29-40%; natrolite, 2730%; nepheline, 5-17%; albite 15%; and aegirine, 5-12%. Grice and Gault (1995) reported the analysis of a single thin-section of rock from the central portion of the sill as follows: K-feldspar, 45%; natrolite, 40%; nepheline, 5%; and aegirine 5% by volume.

Thin sections show the rock to consist of phenocrysts of nepheline in a matrix of K-feldspar laths, prismatic crystals of aegirine, and fine-grained, apparently primary, natrolite. A trachytic texture is imparted by the orientation of the feldspar and aegirine. The K-feldspar laths, consisting principally of microcline and sanidine, are rimmed by albite. Nepheline is partly altered to natrolite and contains inclusions of feldspar and radiating acicular aegirine. Accessory minerals include eudialyte (which may constitute up to 3% of the rock in some zones of the sill), analcime, rinkite and astrophyllite. In the contact zone at the lower margin of the sill, the rock is uniformly fine-grained and much lighter in color than the rest of the sill, probably due to a low concentration or absence of mafic minerals. The rock has a peculiar mottled appearance, with pale gray to brownish gray orbicular patches up to 10 or more cm across surrounded by pale beige to almost white, distinct reaction rims and aureoles. The contact-zone rock has not been examined in thin section.

Reported whole-rock chemical analyses (Table 1) are remarkably consistent, and show no significant difference between the lower contact zone and the bulk of the sill. The composition is typical of nepheline syenites.

The rock is marginally agpaitic with a calculated average agpaitic(1) index of 1.03. Its classification as agpaitic is further supported by a second criterion for agpaicity, the presence of alkaline Ti and Zr-rich silicates and rare-earth minerals (Gerasimovsky, 1956 and 1963). The Saint-Amable sill contains eudialyte, tinkite and astrophyllite both as accessory rock-forming minerals and as cavity minerals. The sill is also remarkable for the relative abundance of other minerals characteristic of agpaitic rocks such as catapleiite, lavenite, lorenzenite and mangan-neptunite, and for the presence of villiaumite, vuonnemite and many rare-earth-element (REE)-bearing minerals such as ancylite-(Ce), bastnasite-(Ce), cordylite-(Ce), monazite-(Ce) and synchysite(Ce). Compared to other agpaitic intrusions, the apparent scarcity or absence of beryllium and boron is notable.

MINERALIZATION

As already noted, the Saint-Amable sill contains many mineralized cavities and seams. These are the source of well-formed microcrystals of interest to collectors. The most abundant, species-rich cavities and seams occur in the upper portions of the sill. They are concentrated in horizontal-trending zones, and are absent where the sill thickness has been reduced by erosion to less than 10-12 meters. Within these zones there are several modes of occurrence of the minerals, distinguished by variations in physical characteristics, associations and paragenesis. A distinctly different type of mineralization is found in the lower contact zone of the sill, and in the similar body of rock exposed in the southwest comer of the Demix-Varennes quarry.

Miarolitic Cavities

The miarolitic cavities are flattened, round to oblong or freeform cavities, commonly 5-10 mm deep and 2-5 cm across. Larger cavities up to 2 cm in depth and 10-20 cm across are rare. Extremely elongated, winding, tubular "worm-hole" cavities, 2-10 mm in diameter and up to 25 cm in length are also found. The miarolitic cavities generally contain clean, sharp, lustrous crystals. They are typically lined with microcline, aegirine and natrolite, which are the earliest minerals in the paragenetic sequence.

The wall rock around miarolitic cavities often contains numerous small, rounded vesicles 1-3 mm across which provide a substrate for a rich and varied assemblage. The mineral assemblage lining these vesicles, and its paragenesis, are almost identical to those of miarolitic cavities, but are more limited in the number of species.

It is likely that the miarolitic cavities were formed by volatiles exsolving from the magma during the final stages of solidification. As degassing progressed, the cavity minerals were deposited from residual alkaline fluids enriched in zirconium, titanium, niobium, rare-earths and other elements. As suggested previously, the cavities were localized between advancing solidification fronts in what was most likely the original center of the sill.

Altered Miarolitic Cavities

Some miarolitic cavities found generally near the erosional surface contain minerals that have been subjected to oxidation and leaching, probably by meteoric water. Serandite is commonly altered to bimessite; eudialyte and some of the aegirine has a bleached appearance; commonly there is an accumulation of a powdery smectite-group mineral; and opal is deposited as a crest on other minerals.

Mineralized Seams

Very narrow, 1-5 mm wide mineralized seams riddled with tiny cavities occur locally in the sill. They are generally horizontal, and can be traced over distances of several meters. During blasting in the quarry, the rock often fractures along these seams, exposing mineralized surfaces up to 2 square meters in area. These seams probably formed as the mineralizing fluids penetrated fissures in the cooling magma. A characteristic of the mineral assemblage, which is similar to that in miarolitic cavities, is an abundance of closely associated astrophyllite, lavenite, rinkite and lorenzenite.

Natrolite Pipes

Some tubular cavities, 2-10 cm in diameter and sometimes up to 2 meters in length, show signs of alteration, and contain very few mineral species other than natrolite. A microcline lining, typical of miarolitic cavities, is rarely present, and many of the pipes are completely devoid of minerals. Natrolite occurs as solid masses, sometimes completely filling the pipes, and as a lining of well-formed crystals forming spherical aggregates 2-3 cm in diameter. The few pipes that have been observed in situ are close to the erosional surface and have a generally vertical orientation. The natrolite pipes may represent post-emplacement, hydrothermal deposition.

Hydrothermalite Pods

Very rarely encountered are pod-like structures having characteristics analogous to those of hydrothermalite bodies associated with other agpaitic alkaline rocks, notably those in the Lovozero massif (Khomyakov, 1995). One of their characteristics is an abundance of Na-rich, highly alkaline minerals. Of the few observed to date, the largest, about 2 meters across, was found in the southeast corner of the Demix-Varennes quarry. it consisted of a series of interconnected, largely infilled cavities roughly spherical to oblong in shape and 20-30 cm in diameter. The margins of the cavities show a zonation from very dense, fine-grained nepheline syenite through a narrow ([approximately] 1 cm wide) alteration zone with evidence of brecciation, to a porous, white, medium-grained intergrowth of natrolite, feldspar and magadiite, with scattered radiating aggregates of acicular aegirine. This intergrowth forms an irregular cavity lining several centimeters thick, and grades into the cavity infilling. The infilling is vuggy and has a texture which suggests that the minerals were deposited in several stages. It consists primarily of crystallized natrolite intergrown with smaller masses of magadiite, polylithionite, nodular chalcedony and other minerals. Varennesite is relatively abundant in this assemblage, both as masses and as crystals in vugs. Also notable is the presence of VUK1, VUK9 and especially shkatulkalite. Most of the minerals in the assemblage have an altered appearance. Peripheral to the large infilled cavities are small cavities with mineralization similar to that of miarolitic cavities. Similar but smaller hydrothermalite pods containing a somewhat different and smaller suite of minerals were also found in the southwest and southeast corners of the quarry.

The genesis of the hydrothermahte pods is unclear. They may represent a very late but localized hydrothermal stage of the sill emplacement, or they may have been formed after emplacement by migrating hydrothermal solutions.

Contact-Zone Cavities

The mineral assemblage in the contact zone of the sill and in a similar body of exposed rock in the south corner of the Demix-Varennes quarry is very different from that in other parts of the sill. The rock is fiddled with numerous cavities, 5-50 mm in size, and often extending over areas of up to several hundred square centimeters. The cavities form interconnected networks in the pale beige to white aureoles around the darker orbicular patches; the shape of the cavities generally conforms to the pattern of the aureoles. The cavities are invariably lined with flattened, poorly formed analcime crystals commonly associated with natrolite, calcite, dolomite and fluorite. Many of the minerals which are common in the rest of the sill, such as aegirine, eudialyte, lavenite, serandite and lorenzenite, are completely absent.

The texture and the mineralogy of the contact zone suggest that while the rock was still hot it was invaded by solutions derived from the underlying shale. The solutions penetrated the rock along a network of fractures, partially dissolving the rock. With further cooling, analcime, natrolite and other minerals crystallized in cavities formed along the fractures. This process would entail little change in overall chemistry since the principal minerals, both in the sill rock and the contact zone cavities, are sodium-aluminum silicates. This would account for the consistency of the chemical analyses of the contact-zone rock and the rest of the sill. The very rare and unusual occurrence of late-stage cryolite, thomsenolite, gibbsite and doyleite in the contact zone is probably analogous to the paragenesis of the hydrothermalite pods.

The observed paragenetic relationships for the three most important assemblages are shown in the accompanying tables.

Table 2. Minerals of the Saint-Amable sill.

Sulfides Arsenopyrite Erdite Galena Lollingite Marcasite Pyrite Pyrrhotite Sphalerite

Oxides & Hydroxides Anatase Birnessite Doyleite Franconite Gibbsite Goethite Hematite Hochelagaite Lueshite Todorokite Woodruffite VUK3

Halides Cryolite Fluorite Thomsenolite Villiaumite

Carbonates Ancylite-(Ce) Ancylite-(La) Aragonite Bastnasite-(Ce) Calcite Cerussite Cordylite-(Ce) Dawsonite Dolomite Donnayite-(Y) Kukharenkoite-(Ce) Rhodochrosite Siderite Strontianite Synchysite-(Ce) VUK11

Sulfates Celestine Gypsum Halotrichite Jarosite

Phosphates Carbonate-fluorapatite Fluorapatite Monazite-(Ce) Rhabdophane-(Ce)

Molybdates Wulfenite

Silicates Aegirine Albite Amphibole grp. Analcime Arfvedsonite Astrophyllite Calciohilairite Catapleiite Chabazite Chlorite grp. Elpidite Epididymite Epistolite Eudialyte Gaidonnayite Gmelinite Hilairite Kaolinite grp. Labuntsovite Lavenite Lemoynite Lorenzenite Magadiite Makatite Mangan-neptunite Microcline Montmorillonite Muscovite Natrolite Nenadkevichite Nepheline Opal Paranatrolite Pectolite Polylithionite Quartz Rinkite Sazhinite-(Ce) Serandite Shkatulkalite Smectite grp. [A and B] Sodalite Terskite Tetranatrolite Thornasite Titanite Tuperssuatsiaite Varennesite (type loc.) Vuonnemite Yofortierite Zakharovite Zircon VUK1 VUK6 VUK7 VUK8 VUK9

MINERALOGY

With the exception of a short abstract (Gault and Horvath, 1993) and the description of the new species varennesite (Grice and Gault, 1995), nothing has been previously published on the mineralogy of the Saint-Amable sill. The following descriptions are based mostly on specimens in the Horvath collection, with supplementary information derived from the collections of Peter Tarassoff and the Canadian Museum of Nature. All species identifications have been confirmed by X-ray diffraction (XRD) methods, supported in many cases by electron microprobe analysis, sometimes on several specimens. It is impractical to include the X-ray data in the present article; however this information is available on request. A number of institutions provided X-ray data and employed the following equipment for routine analyses: Carleton University, Ottawa and the Royal Ontario Museum use 114.6-mm and 57.3mm-diameter Gandolfi single-crystal diffraction cameras generally with CuK[Alpha] radiation; the Canadian Museum of Nature, Ottawa and the Geological Survey of Canada, Ottawa use 114.6-mm Debye-Scherrer powder diffraction cameras generally with CuK[Alpha] (Ni-filtered) radiation.

All chemical analyses were performed on a JEOL 733 electron microprobe using Tracor Northern 5500 and 5600 automation, at the Canadian Museum of Nature, Ottawa. For all analyses reported in this paper, the wavelength-dispersion (WDS) mode was used. Data reduction was accomplished with a conventional ZAF routine in the Tracor Northern TASK series of programs. In all analyses the operating voltage was 15 kV and the beam current was 0.20 [[micro]amperes]. The beam diameter varied according to the type and size of material analyzed. Commonly a 20-30 [[micro]meter] beam diameter was used. Minerals such as carbonates, zeolites and other [H.sub.2]O-bearing minerals, and minerals with high Na content, generally require a beam diameter of at least 40-50 [[micro]meter] to prevent sample burn-up or Na migration/volatilization. The energy-dispersion system (EDS) was frequently used to quickly, check for major elements on many of the specimens, and 100-second EDS scans were used to confirm that no elements with Z [greater than] 8 were missed in the WDS analyses. Only those elements which were detected are reported in the analyses. Samples were also checked for chemical homogeneity using the backscatter electron (BSE) detector. Data for all elements in the samples were collected for 25 seconds or 0.50% precision, whichever was attained first. Data for all elements in the standards were collected for 50 seconds or 0.25% precision, whichever was attained first. Standards used varied with the type of material analyzed. All microprobe analyses were carried out by one of the authors (RAG), and information on standards and operating conditions used in the analyses are available on request.

Species whose identity is presently unknown have been assigned VUK (VUK stands for Varennes unknown) code numbers; these are either potential new species, or species for which the available analytical data are insufficient for definite identification; descriptions of these have also been included. All of the mineral species identified to date are shown in the accompanying table, classified by chemical groups.

Some of the minerals found in the Saint-Amable sill fluoresce under ultraviolet radiation. Their fluorescence characteristics are tabulated (Table 4) as a diagnostic aid to visual identification.

The illustrated specimens, unless otherwise noted in the captions, are from the Horvath collection, and all specimen and locality photos with the exception of the SEM photomicrographs are by L. Horvath. A series of crystal drawings have been included to show typical morphologies of some of the more interesting species. The crystal drawings were made using SHAPE and CorelDRAW software.

Aegirine Na[Fe.sup.3+][Si.sub.2][O.sub.6]

Aegirine is one of the most common and conspicuous minerals in miarolitic cavities, mineralized seams and hydrothermalites. It is found as free-growing, acicular, somewhat flattened prismatic crystals forming divergent sprays and radiating spherical groups, with individual crystals 1-15 mm long. The predominant color is medium to dark green, grading toward a lighter brownish yellow at the terminations. Golden yellow, reddish brown acicular crystals 1-2 mm long, and black prismatic crystals up to 1 cm long are also common.

Aegirine is one of the earliest primary minerals of the sill rock, while in the miarolitic cavities, it is often present as at least two generations, a very early and a mid-stage mineral. It is notably absent in the contact-zone mineralization.

[TABULAR DATA FOR TABLE 3 OMITTED]

Albite NaAl[Si.sub.3][O.sub.8]

Albite, one of the rock-forming minerals, is relatively uncommon as euhedral crystals. It occurs in miarolitic cavities and mineralized seams as sharp, colorless, tabular to thin bladed crystals, 0.5-1.5 mm long, and as colorless, epitactic overgrowths on microcline crystals.

A single microprobe analysis (WDS) of albite gave Si[O.sub.2] 68.59, [Al.sub.2][O.sub.3] 18.66, [Na.sub.2]O 11.66, [K.sub.2]O 0.18, FeO trace, total 99.09 weight % resulting in the empirical formula [([Na.sub.1.00][K.sub.0.01]).sub.[Sigma]1.01] [Al.sub.0.97]-[Si.sub.3.02][O.sub.8], based on 8 oxygen atoms. Ca was specifically sought but not detected.

Amphibole group

An amphibole-group mineral is found rarely in altered miarolitic [TABULAR DATA FOR TABLE 4 OMITTED] cavities, as fibrous tufts and as dark green to black acicular crystals up to 1.5 mm long. The exact identity of the species has not been determined.

Analcime NaAl[Si.sub.2][O.sub.6] [multiplied by] [H.sub.2]O

Analcime is the dominant species in cavities in the contact zone, where it lines nearly all the cavity walls in crystals from a few millimeters to 5 cm in diameter. The crystals are opaque, white to tan, poorly formed, flattened, invariably intergrown and rarely show more than a few crystal faces. Analcime is relatively rare in miarolitic cavities, where it occurs as colorless trapezohedra to 1 mm, with many inclusions, and as opaque, white or grayish white, rather poorly formed, partially etched, 1-20 mm crystals. The latter are similar to and easily mistaken for intergrown natrolite crystals found in some cavities.

Analcime is one of the earliest minerals in the paragenetic sequence of the contact-zone assemblage, whereas in the miarolitic cavities it appears to be a mid to late-stage species.

Anatase Ti[O.sub.2]

Anatase is relatively uncommon in miarolitic cavities. It occurs as groups of sharp, equant, transparent, lemon-yellow or pale green, 0.3-0.6 mm dipyramidal crystals bounded by the {111} pyramids and small {001} basal pinacoids. It also forms translucent to opaque, pale gray to greenish blue to dark blue, thin to thick tabular crystals 0.5-1.5 mm in diameter, dominated by {001} pinacoids; dmses of tiny steel-blue plates 0.1-0.3 mm across; and opaque, dark green to black, square tabular crystals 1-2 mm across with peculiar rounded comers and etched basal pinacoids.

Ancylite-(Ce) SrCe[(C[O.sub.3]).sub.2](OH) [multiplied by] [H.sub.2]O

A relatively uncommon late-stage mineral in miarolitic and contact-zone cavities, ancylite-(Ce) occurs as sharp, transparent, colorless to pale yellow and very rarely pale pink, slender, commonly doubly terminated prismatic crystals, 0.6-3.0 mm long, typically forming divergent, fan-shaped groups. In both associations the crystal morphology is identical, consisting of an elongated {120} prism terminated by the {111} rhombic pyramid. The luster varies from vitreous to greasy.

Ancylite-(La) Sr(La,Ce)[(C[O.sub.3]).sub.2] [multiplied by] (OH) [multiplied by] [H.sub.2]O

Electron microprobe (EDS) and XRD analyses identified the Ladominant analog of ancylite-(ce), ancylite-(La), which has recently been described from Mount Kukisvumchorr Khibiny massif, Kola Peninsula, Russia (Yakovenchuk et al., 1997). It occurs very rarely in miarolitic cavities as vitreous, sharp, transparent, colorless to pale yellowish gray prismatic crystals 0.5-0.8 mm long, forming fan-like and spherical groups. Crystal morphology is identical to that of ancylite-(Ce). The probe analysis also indicates minor Ca and Th content. These crystals will require further investigation.

Aragonite CaC[O.sub.3]

Aragonite is uncommon in the cavities of the contact zone, occurring as opaque, dull, white, fibrous tufts, and as somewhat crude, acicular crystals forming hollow, spherical aggregates 2-3 mm in diameter. It fluoresces bluish white under both shortwave and longwave ultraviolet radiation.

Arfvedsonite [Na.sub.3][([Fe.sup.2+],Mg).sub.4][Fe.sup.3+][Si.sub.8][O.sub.22][(OH).sub.2]

Arfvedsonite is rare, and has been observed in only a few miarolitic cavities that show evidence of alteration. It occurs as very dark green to black, 1-4 mm short prismatic crystals often partially enclosed in natrolite. The luster varies from vitreous on prism faces, to dull on the terminations.

Arsenopyrite FeAsS

An extremely rare mineral in miarolitic cavities, arsenopyrite is found as silvery, metallic, equant, wedge-shaped crystals 0.4-1.0 mm across, forming complex aggregates. (Arsenopyrite is very similar in appearance to, and difficult to distinguish from, lollingite.)

Astrophyllite [(K,Na).sub.3][([Fe.sup.2+],Mn).sub.7][Ti.sub.2][Si.sub.8][O.sub.24][(O,OH).sub.7]

Astrophyllite is a very common species in the sill, occurring as a rock-forming accessory mineral and also as well-formed crystals in miarolitic cavities and mineralized seams. In miarolitic cavities it is found as superb, transparent to translucent, reddish brown to orange brown, tapering tabular crystals 1-5 mm long. Crystals consist of a dominant {100} pinacoid bounded by somewhat rough, often striated, bevelled edges which are difficult to index. The crystals often form attractive fan-shaped groups and rosettes. The luster is vitreous on the pinacoids, and waxy to dull on all other faces. Astrophyllite is also found as thin rectangular sheets and somewhat fibrous, radiating aggregates with a waxy luster.

Astrophyllite is one of the earliest species in miarolitic cavities and mineralized seams, associated with practically all species found in these assemblages. It is notable that the contact zone of the sill is completely devoid of the mineral.

A single microprobe analysis (WDS) of astrophyllite gave [K.sub.2]O 5.73, [Na.sub.2]O 2.81, CaO 1.07, SrO 0.09, FeO 19.23, MnO 15.48, MgO 0.38, Ti[O.sub.2] 10.72, [Nb.sub.2][O.sub.3] 1.27, Zr[O.sub.2] 0.98, Si[O.sub.2] 35.49, [Al.sub.2][O.sub.3] 0.32, F 1.05, [H.sub.2]O 4.36 (calculated by stoichiometry) O = F -0.44, total 98.55 weight %, resulting in the empirical formula: [([K.sub.1.58][Na.sub.1.18][Ca.sub.0.25][Sr.sub.0.01]).sub.[Sigma]3.02] [([Fe.sub.3.47][Mn.sub.2.83][Mg.sub.0.12]).sub.[Sigma]6.42] [([Ti.sub.1.74][Nb.sub.0.12][Zr.sub.0.10]).sub.[Sigma]1.96-] [([Si.sub.7.66][Al.sub.0.08]).sub.[Sigma]7.74][O.sub.23.96][[(OH).sub.6.32][F.sub.0.72].sub.7.14] based on 31 anions.

Bastnasite-(Ce) (Ce,La)(C[O.sub.3])F

Bastnasite-(Ce) occurs as a very rare, late-stage mineral in both miarolitic and contact-zone cavities. In miarolitic cavities it is found as translucent to opaque, silvery gray, micaceous hexagonal plates 2-3 mm in diameter; as beige to white rosettes 0.5-1 mm in diameter, with a pearly luster; and as aggregates of minute, pearly, pale gray to white flakes less than 0.2 mm across. The larger hexagonal crystals show concentric zoning, with a translucent, pale gray zone around the edges, becoming darker and opaque in the center. Associated minerals are microcline, natrolite, catapleiite, astrophyllite, labuntsovite, mangan-neptunite, aegirine, rhodochrosite and pyrrhotite. In the contact-zone cavities it is found as pale gray, somewhat fibrous, acicular crystals forming divergent sprays and spherical aggregates 0.5-1.0 mm in size associated with analcime, siderite, calcite, pyrite and sphalerite.

Birnessite [Na.sub.4][Mn.sub.14][O.sub.27] [multiplied by] 9[H.sub.2]O

Birnessite, a late-stage alteration product, has been found in altered and weathered miarolitic cavities as sharp, well-formed pseudomorphs after serandite, and as thin crusts and small masses. The pseudomorphs form equant to elongated blocky crystals up to 1 cm long, and bladed crystals 2-8 mm long, associated most frequently with microcline, natrolite, aegirine, eudialyte, opal and mangan-neptunite. Crystals are black with a submetallic to dull luster on the faces, and resinous to dull black luster on freshly broken surfaces. Many of the crystals and crusts exhibit irregular, natural cracking. As observed at Mont Saint-Hilaire (Horvath and Gault, 1990), the pseudomorphs very clearly exhibit the morphology and habit of the precursor serandite.

Birnessite is regarded as a solid solution series, having variable composition, unit cell parameters and X-ray diffraction pattern (Kim, 1980). Kim proposed that birnessite should be considered a mineral group, with individual, Ca, [Mn.sup.2+] and Na end-members. Although difficult to analyze, microprobe analyses (EDS) carried out on several specimens clearly indicate that the Saint-Amable birnessite is Ca-dominant with only a trace of Na present. The XRD pattern is identical to that reported from the type locality (Jones and Milne, 1956).

Calciohilairite CaZr[Si.sub.3][O.sub.9][multiplied by]3[H.sub.2]O

Calciohilairite was described as a new species from the Golden Horn batholith in the northern Cascade Mountains, Washington (Boggs, 1988). The Saint-Amable sill is the second known occurrence of the mineral. Recently, it was also identified from Mont Saint-Hilaire (G. Y. Chao, personal communication, 1996), and an intermediate composition between hilairite and calciohilairite has been reported from the Strange Lake alkaline complex on the Quebec-Labrador border, Canada (Birkett et al., 1992).

Calciohilairite is extremely rare in the Saint-Amable sill, with only two confirmed specimens known from two separate finds, both in miarolitic cavities. In one it occurs as opaque, pale beige, somewhat crudely formed, short trigonal prisms 0.6-0.9 mm long, with rhombohedral terminations and a dull luster. These crystals are similar to the somewhat altered calciohilairite found at the type locality. The crystals are found in small, interconnected, boxwork cavities in a mass of intergrown natrolite crystals associated with nenadkevichite, rhodochrosite, polylithionite, fluorite, aegirine and pyrite.

In the second specimen, from an altered miarolitic cavity, calciohilairite occurs as sharp, white, blocky crystals 0.5-0.8 mm in size, having a pearly luster and forming intergrown aggregates on birnessite pseudomorphs after serandite. Associated minerals are astrophyllite, aegirine, eudialyte, microcline, mangan-neptunite and natrolite. In both assemblages calciohilairite is a late-stage mineral in the paragenetic sequence.

Calciohilairite was confirmed by single-crystal X-ray diffraction and an electron microprobe (WDS) analysis which gave the formula: [([Ca.sub.0.99][K.sub.0.01]).sub.[Sigma]1.00] [([Zr.sub.0.96][Ti.sub.0.02][Mn.sub.0.01]).sub.[Sigma]0.99][([Si.sub.3.00][Al.sub.0.01]).sub.[Sigma]3.01] [O.sub.8.98] [multiplied by] 3[H.sub.2]O. Sodium was specifically sought, but not detected in the analysis, confirming the mineral to be pure end-member calciohilairite.

Calcite CaC[O.sub.3]

Calcite is very common, especially in the contact-zone cavities in which it occurs as colorless druses and as well-formed, colorless to pale yellow simple rhombs and complex crystals 1-2 mm in size. It is also a common late-stage mineral in miarolitic cavities as transparent, pale to lemon-yellow scalenohedra up to 5 mm long; as white, acicular crystals; and as translucent to opaque, yellow botryoidal aggregates, often with dull, frosty surfaces. Calcite fluoresces strong whitish yellow under shortwave and strong orange-yellow under longwave ultraviolet radiation, in some specimens retaining a weak whitish yellow phosphorescence for a very short duration.

Carbonate-fluorapatite [Ca.sub.5][(P[O.sub.4],C[O.sub.3]).sub.3]F

A very rare, late-stage mineral in miarolitic cavities, carbonate-fluorapatite occurs as spherical aggregates 0.5-1.0 mm in diameter composed of thin, rounded colorless to very pale yellow plates having a vitreous luster.

Catapleiite [Na.sub.2]Zr[Si.sub.3][O.sub.9] [multiplied by] 2[H.sub.2]O

Catapleiite is one of the characteristic species found in agpaitic alkaline rocks, either as a primary mineral or as an alteration product of eudialyte. In the Saint-Amable sill, both types are present. Primary catapleiite is very rare in the miarolitic cavities, occurring as sharp, colorless, very thin pseudohexagonal plates 0.5-1.0 mm in diameter, with a vitreous luster. Secondary catapleiite is more common, occurring as irregular, pearly, opaque, silvery gray, micaceous plates 0.2-0.4 mm in diameter which form cellular aggregates and crude pseudorhorphs replacing eudialyte. These occasionally enclose relict fragments of eudialyte.

Primary catapleiite is relatively common in cavities in the contact zone as thin, translucent, colorless, pale beige to white pseudohexagonal plates 0.5-2.0 mm in size, forming attractive rosettes and spherical groups up to 4 mm in diameter. The crystals are very sharp and have a vitreous to pearly luster. Some of the catapleiite in this association fluoresces a weak, pale orange yellow under shortwave ultraviolet radiation.

The primary catapleiite found in the miarolitic and contact-zone cavities appears to be one of the mid-stage minerals in the paragenesis. The secondary catapleiite found in miarolitic cavities is a relatively late-stage species. Associated minerals include practically all the species found in the sill.

Celestine SrS[O.sub.4]

Celestine is rare, occurring in the contact-zone cavities as radiating groups of colorless, prismatic crystals 1-4 mm long, and as opaque, white, somewhat fibrous radiating aggregates forming crude spheres, with the colorless prisms protruding from the spheres. Luster varies from vitreous to dull.

Cerussite PbC[O.sub.3]

An extremely rare secondary mineral in miarolitic cavities, cerussite is found as thin opaque, white to tan crusts on galena crystals.

Chabazite Ca[Al.sub.2][Si.sub.4][O.sub.12] [multiplied by] 6[H.sub.2]O

Chabazite is extremely rare, occurring as colorless, hexagonal plates 0.2-0.5 mm in diameter, forming spherical aggregates in miarolitic cavities.

Chlorite group

Aggregates of minute micaceous plates of a chlorite-group mineral admixed with fibrous fluorapatite and also with foliated masses of monazite-(Ce) were identified from a number of miarolitic cavities.

Cordylite-(Ce) BaNa[Ce.sub.2][(C[O.sub.3]).sub.4]

Cordylite-(Ce) was first described from Narssarssuk in South Greenland (Flink, 1901); it was later reported from Mont Saint-Hilaire (Chen and Chao, 1975), and Bayan-Obo, Inner Mongolia, China (Zhang and Tao, 1985). The chemical data presented in these descriptions did not show the presence of any sodium, which appears to be at variance with more recent work by Shen Jinchuan and Mi Jinxiao (1992a and b), a group of investigators in Europe (J. Zemann, personal communication, 1996) and one of the present authors (RAG). In conjunction with the study of cordylite-(Ce) from the Saint-Amable sill, which is the fourth reported locality for the mineral (Gault and Horvath, 1993), electron microprobe analyses were also performed on cordylite-(Ce) from Narssarssuk and Mont Saint-Hilaire. The results confirm that essential sodium is present in cordylite-(Ce) from all these localities, and the compositions are consistent with those reported for baiyuneboite-(Ce) described from Bayan-Obo (Fu and Kong, 1987; Fu and Su, 1988). The species status of baiyuneboite-(Ce) is doubtful (Fleischer and Mandarino, 1995), but it has not been discredited. Recently, cordylite-(Ce) has also been reported from the Khibina massif, Kola Peninsula, Russia (Khomyakov, 1995) but no chemical data are given.

A partial microprobe analysis (WDS) of cordylite-(Ce) from the Saint-Amable sill gave [Na.sub.2]O 3.96, BaO 20.91, SrO 0.74, CaO 0.36, [La.sub.2][O.sub.3] 14.73, [Ce.sub.2][O.sub.3] 23.85, [Pr.sub.2][O.sub.3] 1.46, [Nd.sub.2][O.sub.3] 4.90, [Sm.sub.2][O.sub.3] 0.21, F 2.64, C[O.sub.2] 24.50 (F and C[O.sub.2] calculated by stoichiometry), O = F -1.11, total 97.15 weight %, based on 13 anions resulting in the empirical formula: [Na.sub.0.92][([Ba.sub.0.98][Sr.sub.0.05][Ca.sub.0.04]).sub.[Sigma]1.07]([La.sub.0.65][Ce.sub.1.05-]

[[Pr.sub.0.06][Nd.sub.0.21][Sm.sub.0.01]).sub.[Sigma]1.98][(C[O.sub.3]).sub.4]F.

Cordylite-(Ce) is relatively rare, although surprisingly abundant locally, as a very late-stage species in miarolitic cavities and in mineralized seams. Two distinct crystal habits have been observed: very rare, short hexagonal prisms, and more common, thin to thick, tabular hexagonal crystals. The prismatic crystals are 1-2 mm long, greenish gray, opaque, with a greasy luster, and terminated by {0001} basal pinacoids. Prism faces are striated parallel to the basal pinacoids, and a good basal cleavage and a layered structure are evident in broken crystals.

Tabular crystals are colorless, transparent to translucent, pale yellow, amber-yellow, opaque gray, greenish gray and white. They are 0.5-1.5 mm across, are dominated by the {0001} basal pinacoid, and often form rosettes and complex, stacked, curved barrel-shaped groups. Other forms observed are the small {1000} prism, and very rarely the {10h1} pyramid. Luster varies from vitreous on some basal pinacoids to pearly or dull and frosty on all other crystal faces, whereas cleavages or broken surfaces are resinous. Some of the thin tabular crystals exhibit concentric, alternating transparent and opaque zones on the basal pinacoids. Cordylite-(Ce) has also been found as compact, spherical aggregates up to 1 mm in diameter, consisting of silvery, micaceous, very thin hexagonal plates.

In one particular, localized assemblage, an unusually high concentration of very thin, tabular crystals was observed intimately associated with and adjacent to masses of dark gray aggregates of catapleiite with altered, relict fragments of eudialyte, zakharovite, fluorite, elpidite, pyrrhotite, rhodochrosite and labuntsovite. This mineral assemblage appears to be the result of the alteration of eudialyte. It occurred in a zone characterized by a parallel series of very narrow (2-3 mm wide), peculiar sinusoidal seams, spaced 35 cm apart and generally oriented parallel to the sill horizon. Other associated minerals are natrolite, aegirine, serandite, manganneptunite, microcline, astrophyllite, nenadkevichite, quartz and pyrite.

Cryolite [Na.sub.3]Al[F.sub.6]

In a very rare and unusual occurrence, cryolite was found as cavity fillings in the contact zone of the sill exposed in the southeastern part of the Demix quarry in December of 1996. Masses of colorless cryolite up to 10 cm in diameter are enclosed in cellular aggregates consisting of white to pale beige powdery gibbsite, and drusy crusts and aggregates of colorless thomsenolite crystals. The cryolite masses are strongly corroded, with step-like etch-features; crude, partially dissolved crystals are visible on some specimens. The cryolite has a frosty appearance but is quite transparent; the luster varies from vitreous to waxy. It fluoresces intense yellowish white under shortwave ultraviolet radiation, with short-duration pale yellow phosphorescence; under longwave radiation it fluoresces a weak yellowish white.

Cryolite is a late-stage mineral in the paragenetic sequence, and its deposition is probably the result of hydrothermal action. Associated minerals in addition to gibbsite and thomsenolite are doyleite, pyrrhotite, sphalerite, galena, pyrite and a pale yellow unidentified mineral.

Dawsonite NaAl(C[O.sub.3])[(OH).sub.2]

Dawsonite is a relatively common species in the western Monteregian intrusions, and was the first new mineral species described from the alkaline rocks in this area (Harrington, 1875 and 1878; Graham, 1908).

Dawsonite is very rare in the Saint-Amable sill. It is found as crude, colorless, prismatic crystals, forming embedded masses to 5 mm across in the light-colored aureoles around cavities of the contact zone. Individual crystals are 2-3 mm long, longitudinally striated, somewhat fibrous, and lack distinct terminations. Dawsonite has also been found in a hydrothermalite pod as sharp, colorless, terminated prismatic crystals, 1-3 mm long. The crystals are bounded by dominant {110} prisms and {100} pinacoids, with a usually very small {010} pinacoid, and are terminated by the basal pinacoid {001}; some crystals show a small {011} prism. Crystal faces in the prism zone are invariably striated parallel to the c-axis, giving the crystals a silky luster. Associated minerals in the contact zone are natrolite, analcime, catapleiite, franconite, hematite, hochelagaite, siderite and calcite, whereas in the hydrothermalite pod they are natrolite, varennesite, makatite, serandite, eudialyte and zakharovite.

Dawsonite is one of the early species in the paragenesis of the contact zone, whereas in the hydrothermalite pod it is one of the late-stage minerals. Exceedingly rarely, it has also been observed as a very late-stage mineral in contact-zone cavities, occurring as silky white, powdery to finely fibrous aggregates and as spherical groups of short, radiating, capillary crystals.

Dolomite CaMg[(C[O.sub.3]).sub.2]

Dolomite has been identified from cavities in the contact zone, where it occurs frequently as crude, blocky, pale yellow to grayish green, 0.5-1 mm crystals; as sharp, equant, colorless, complex 1-1.5 mm crystals on analcime; and as pale pink, 3-5 mm, simple rhombic and saddle-shaped crystals. Rarely, dolomite has also been found in miarolitic cavities as white and pale pink spheres and as irregular, pale yellow aggregates.

Donnayite-(Y) [Sr.sub.3]NaCaY[(C[O.sub.3]).sub.6] [multiplied by] 3[H.sub.2]O

Donnayite-(Y) was first described from Mont Saint-Hilaire (Chao et al., 1978). It was later reported from Vishnevye Gory, South Urals (Nikandrov, 1989), and from the Khibina massif, Kola Peninsula (Khomyakov, 1990 and 1995), both in Russia. The Saint-Amable sill is the fourth known locality for the species.

Donnayite-(Y) is extremely rare, and is found in cavities in the contact zone as crude, equant, opaque, beige to yellowish white hemimorphic crystals 0.5-1.0 mm in size, having a roughly hexagonal to circular cross-section, and dominated by a {001} basal pinacoid. Some crystals are hollow shells with a powdery white or brown unidentified mineral partially filling some of the shells. Rarely, multiple pagoda-shaped pseudohexagonal crystals grow from a common base in parallel groups. Donnayite-(Y) has also been found in miarolitic cavities as opaque, beige, 0.5-1.5 mm, bell-shaped hemimorphic crystals with a nearly circular cross section, and a {001} basal pinacoid as the only distinct form observed. The prism zone is covered by small donnayite-(Y) crystals in parallel growth. The luster is waxy on the dominant pinacoid and dull on all other surfaces. Donnayite-(Y) was also found as transparent, pale yellow and salmon-pink, tapering prismatic and short hemimorphic crystals 0.5-1.0 mm across having a well-defined, hexagonal cross section. These crystals are vitreous with unusually sharp, step-like features on the prism faces.

In the Khibina massif two polytypes of donnayite-(Y), a trigonal and a triclinic, have been reported (Trinh et al., 1992; Khomyakov, 1990 and 1995). In the Saint-Amable sill, only the triclinic polytype has been identified. It is one of the latest minerals in the paragenesis of both assemblages. Most typical associated minerals are analcime, dolomite, pyrrhotite, siderite, catapleiite and pyrite in the contact-zone cavities, and microcline, aegirine, natrolite and elpidite in the miarolitic cavities.

Doyleite Al[(OH).sub.3]

Doyleite, a very rare polymorph of gibbsite and bayerite, was described as a new species from Mont Saint-Hilaire, and simultaneously from the Saint-Michel sill (Francon quarry) in Montreal (Chao et al., 1985). The Saint-Amable sill is the third known locality for the mineral. Recently, doyleite was also reported from Grube Clara, Wolfach, Germany (Walenta, 1993).

Doyleite is very rare in the Saint-Amable sill, occurring as a late-stage mineral in miarolitic cavities. It was first identified in 1986 from a specimen collected in 1982, in which it was observed as small, opaque, beige, irregular masses (A. P. Sabina, and A. C. Roberts, personal communications). Doyleite with a minor admixture of fluorite was found in miarolitic cavities as rosette-like aggregates of opaque, waxy, white, tabular crystals 0.3 - 0.6 mm across. Crystals are rectangular or square in outline and gently taper from a thicker center to thinner outer edges. Associated minerals are microcline, eudialyte, yofortierite, astrophyllite, serandite and aegirine. Recently doyleite was also found in contact-zone cavities as white, powdery aggregates admixed with gibbsite and associated with thomsenolite and cryolite.

Elpidite [Na.sub.2]Zr[Si.sub.6][O.sub.15] [multiplied by] 3[H.sub.2]O

Elpidite is relatively common in miarolitic cavities, where it occurs as pale to bright orange, brownish yellow, orange-yellow and beige aggregates of short to elongated 0.5-1.5 mm prisms with chisel-shaped terminations. Most crystals are doubly-terminated and rather simple, consisting of a short {110} prism terminated by a {011} prism. Less commonly, the crystals are modified by the {010} pinacoid. Crystals are opaque with some translucency at thin edges and the terminations; the luster varies from predominantly vitreous to waxy. In this paragenesis, elpidite is a mid to late-stage mineral, and is associated with most of the species found in the miarolitic cavities.

Crystals of elpidite bear a close resemblance to and may be difficult to distinguish from labuntsovite, to which it is structurally related. The two species often occur together, sometimes in an epitactic relationship with labuntsovite growing on or enclosing elpidite. As the predominant color of elpidite is shades of orange rather similar to that of labuntsovite, visual identification based on color is unreliable. However, the opacity of elpidite, and the transparency of labuntsovite combined with the presence of the {001} basal pinacoid on labuntsovite, are reasonably good distinguishing features.

Epididymite NaBe[Si.sub.3][O.sub.7](OH)

Epididymite, the only beryllium-bearing mineral identified to date from the locality, is extremely rare. It is found as colorless, short prismatic crystals 0.2-0.5 mm long, forming complex intergrown clusters in miarolitic cavities. Individual crystals are colorless, but the clusters appear white and opaque, with a vitreous luster. The few identified specimens were collected in 1994 in the southwest corner of the Demix pit. The crystals are very small and may be easily overlooked or confused with the more abundant clusters of short prismatic nenadkevichite.

Epididymite appears to be one of the late minerals in the paragenesis, and is associated with microcline, natrolite, aegirine, astrophyllite, mangan-neptunite and pyrrhotite.

Epistolite [Na.sub.2][(Nb, Ti).sub.2][Si.sub.2][O.sub.9] [multiplied by] n[H.sub.2]O

Epistolite was originally described from Ilimaussaq, Greenland (Boggild and Winther, 1901; Karup-Moller, 1986a), and has also been found in the Lovozero massif, Kola Peninsula, Russia (Semenov, 1961), and at Mont Saint-Hilaire, Quebec (Mandarino and Anderson, 1989). The Saint-Amable sill is the fourth documented locality for the mineral. It has been identified from a miarolitic cavity, as a single specimen collected in 1994 in the southwest corner of the Demix quarry. It occurs as vitreous, transparent, pale yellow, very thin, elongated, rectangular blades 2-3 mm long. Associations include microcline, natrolite, aegirine and mangan-neptunite. Epistolite is essentially identical in appearance to its precursor mineral, vuonnemite, and to shkatulkalite.

Epistolite is a mineral that is known only as pseudomorphs after vuonnemite, and belongs to an interesting special class of homoaxial pseudomorphs (Khomyakov, 1995) in which the secondary mineral retains the chemical and structural properties of the primary species.

Erdite NaFe[S.sub.2] [multiplied by] 2[H.sub.2]O

Erdite was originally described from Coyote Peak, California (Czamanske et al., 1980), and later reported from the Lovozero massif (Khomyakov et al., 1982) and Mont Saint-Hilaire (Horvath and Gault, 1990). The Saint-Amable sill is the fourth locality known for the mineral; it was identified from a single miarolitic cavity.

Erdite occurs as sharp, opaque, coppery, prismatic crystals (possibly pseudomorphs) up to 1 mm long, having a submetallic luster and forming parallel, intergrown groups. It was identified by XRD and microprobe analysis (EDS), with the XRD also indicating the presence of minor pyrite. It appears to be a late-stage mineral, associated with aegirine, eudialyte, nenadkevichite and an unidentified red X-ray amorphous mineral.

Eudialyte [Na.sub.15][Ca.sub.6][Mn.sub.3]Nb[Zr.sub.3][Si.sub.26][O.sub.76][F.sub.2]

Eudialyte is one of the most characteristic and ubiquitous minerals in miarolitic cavities and hydrothermalite pods. A very complex mineral chemically, eudialyte is one of the key minerals in the paragenesis of both types of occurrences, and through its alteration contributes significantly to the proliferation of mineral species in these assemblages. It is also an important constituent (estimated 2-3%) of some zones of the sill rock and, as the most abundant Zr and REE mineral, it is an important factor in the geochemistry of the Saint-Amable sill.

Eudialyte alters readily, mainly as a result of rising alkalinity (Khomyakov, 1990 and 1995), to species such as catapleiite and terskite which are found in many miarolitic cavities; it most likely also contributes to the late-stage formation of species like labuntsovite, nenadkevichite, cordylite-(Ce), zakharovite and possibly varennesite.

Eudialyte occurs as excellent, sharp, thin to thick tabular crystals 2-5 mm across, most commonly forming parallel stacked or rosette-like aggregates. Most crystals have a relatively simple morphology, with dominant {0001} basal pinacoid combined with the {1011} positive rhombohedron and the {1120} prism. Rarely, the {0221} negative rhombohedron and {1010} prism are also present. It is interesting to note that only the thin tabular habit has been observed to date. Crystals are mostly transparent, with occasional opaque central cores and dull, opaque surface zones, possibly indicating some degree of surface alteration. The color of unaltered crystals varies from pale to dark pink, pale orange-red, carmine-red and reddish brown, whereas altered crystals exhibit gray, tan, yellowish and white surface coloration. The luster varies from vitreous on fresh crystals, to dull and waxy on altered crystals. Inclusions and internal fractures are present in most crystals.

Eudialyte also occurs as embedded crystals and irregular grains in the sill rock, from the highest concentration around miarolitic cavities to total absence in the contact zone. It is present as one of the early minerals in the miarolitic cavities, but the majority of the crystals are late-stage in the paragenesis.

During a current, collaborative study of eudialyte carried out by the Geologisk Museum, University of Copenhagen, and the Canadian Museum of Nature, one of the authors (RAG) performed microprobe analyses on specimens from worldwide localities, including the Saint-Amable sill. The results indicated a wide variation in composition (Johnsen and Gault, 1997). As a general rule, the Saint-Amable eudialyte is low in Nb, Ca and Fe, and high in Na, Mn and Si compared to eudialytes from elsewhere. The problem of calculating eudialyte formulae is complex and is discussed in Johnsen and Gault (1997). They suggest that without a structure refinement, the best procedure for calculating the formula is to base it on 78 anions. This procedure minimizes the potential errors in calculations which can be introduced by other methods. The following is an average of five analyses: Si[O.sub.2] 48.18, Zr[O.sub.2] 9.88, [Na.sub.2]O 16.94, CaO 4.29, FeO 2.63, MnO 6.43, [K.sub.2]O 0.46, [La.sub.2][O.sub.3] 1.69, [Ce.sub.2][O.sub.3] 2.70, [Nd.sub.2][O.sub.3] 0.53, [Y.sub.2][O.sub.3] 0.71, [Nb.sub.2][O.sub.5] 1.34, [Al.sub.2][O.sub.3] 0.15, SrO 0.17, Ti[O.sub.2] 0.85, Hf[O.sub.2] 0.13, Cl 0.37, F 0.49, [H.sub.2]O 0.82 (calculated by stoichiometry), O = Cl -0.08, O = F -0.21, total 98.47 weight %. based on 78 anions the resultant empirical formula is: [([Na.sub.16.63] [K.sub.0.32] [Y.sub.0.21] [Sr.sub.0.05]).sub.[Sigma]17.21] [([Ca.sub.2.50][Mn.sub.1.27][Na.sub.1.25][REE.sub.0.98)].sub.[Sigma]6.00][([Mn.sub.1.70][Fe.sub.1.20][Al.sub.0.10]).sub .[Sigma]3.00] [Nb.sub.0.33][Si.sub.2.23][(Zr.sub.2.62][Ti.sub.0.35][Hf.sub.0.02]).sub.[Sigma]2.99][([Si.sub.3][O.sub.9]).sub.2][([Si. sub.9][O.sub.27]).sub.2]-[O.sub.4.02][([F.sub.0.84]O[H.sub.0.82][Cl.sub.0.34]).sub.[Sigma]2.00]. A single microprobe analysis on an altered crystal shows a large increase in Ca and Ti contents, and a large decrease in Mn relative to the analysis on unaltered material. Faint concentric, chemical zoning, particularly with regard to the elements Ca, Fe, Mn, Nb and REE, is evident in all crystals examined with the BSE detector.

Fluorapatite [Ca.sub.5][(P[O.sub.4]).sub.3]F

Fluorapatite is very rare and inconspicuous in miarolitic cavities, occurring as colorless to white, fine acicular and fibrous tufts 0.51.0 mm long; as opaque, white, crude blocky crystals up to 1 mm in size, and as opaque, gray, hollow spheres 1-3 mm in diameter.

Fluorite Ca[F.sub.2]

Fluorite is relatively common in miarolitic and contact-zone cavities. In cavities of the contact zone it is found as opaque, crude, pure white, blocky pseudomorphs after an unknown mineral, up to 1 mm across; as sharp, transparent, color-zoned cubes up to 1 mm across, with pale purple cores and dark purple outer zones; as extremely rare translucent, pale blue, 0.5-0.8 mm cubes; and as crude, translucent, pale purple, 1-2 mm cubes with peculiarly rounded and etched surfaces.

In miarolitic cavities, fluorite occurs as colorless, transparent, pale yellow, pale green and purple cubes and cuboctahedra to 1 mm in diameter; as white, silky, bent and twisted fibrous tufts and masses indistinguishable froth other white fibrous minerals; as thin, colorless, white and pale purple coatings, crusts and hollow spherical shells; and as white stalagmitic and curved "ram's horn" aggregates. It has also been found in an altered miarolitic cavity as unusual spherical aggregates of acicular to fibrous crystals, possibly pseudomorphs after strontianite. The spherical aggregates are 2-4 mm in diameter and vivid purple with dull to greasy luster. Some of the fluorite fluoresces a weak pale blue under shortwave ultraviolet radiation.

Fluorite is a late-stage mineral in all assemblages, and is associated with essentially all the species found in the sill.

Franconite [Na.sub.2][Nb.sub.4][O.sub.11] [multiplied by] 9[H.sub.2]O

Franconite was described as a new species from the Saint-Michel sill (Francon quarry) in Montreal by Jambor et al. (1984). It has also been found at Mont Saint-Hilaire (Chao and Baker, 1979 [UK43]; Mandarino and Anderson, 1989), and Vishnevye Gory, South Urals, Russia (Nikandrov, 1989). The Saint-Amable sill is the fourth known locality for the mineral (Gault and Horvath, 1993).

Franconite is found very rarely in cavities in the contact zone and also in miarolitic cavities, as silky, pure white, extremely thin capillary fibers forming radiating spherical aggregates up to 1 mm in diameter. It is identical in appearance to, and visually indistinguishable from the much rarer hochelagaite also found in the sill. It fluoresces yellowish white under both shortwave and longwave ultraviolet radiation.

Franconite is one of the late-stage minerals in the paragenesis, associated with analcime, natrolite, catapleiite, dolomite, fluorite and dawsonite in the contact-zone cavities, and with natrolite, aegirine, eudialyte, serandite, astrophyllite and yofortierite in miarolitic cavities.

Gaidonnayite [Na.sub.2]Zr[Si.sub.3][O.sub.9] [multiplied by] 2[H.sub.2]O

Gaidonnayite was described as a new species from Mont Saint-Hilaire (Chao and Watkinson, 1974; Chao, 1985). Many occurrences have been reported since then in other alkaline intrusions, including Narssarssuk, Greenland; the Khibina and Lovozero massifs in Russia; the Langesundfjord area in Norway; the Pocos de Caldas complex, in Brazil; in an igneous sill in Montreal-Est, and in the Kipawa complex, both in Quebec, Canada.

Gaidonnayite is extremely rare in the Saint-Amable sill, and known only from a single specimen from a slightly altered miarolitic cavity. It occurs as druses and clusters of small, equant, colorless, intergrown crystals measuring 0.2-0.5 mm across and having a vitreous luster. No fluorescence was observed under ultraviolet radiation. Gaidonnayite may be locally more common than the single identified specimen suggests, but may be easily overlooked due to the small size of the crystals, its inconspicuous appearance, and the lack of fluorescence.

Gaidonnayite is a relatively late-stage mineral, associated with natrolite, bastnasite-(Ce), aegirine, astrophyllite and altered eudialyte.

Galena PbS

Galena occurs frequently in the miarolitic cavities as sharp, 1-1.5 mm cubes rarely modified by small octahedral faces. In addition to the cubic crystals, two unusual habits have been observed: elongated crystals resembling tetragonal prisms, and very thin, sometimes bent, rectangular to irregular foil-like plates which are similar in appearance to molybdenite. Along with sphalerite, galena is one of the late minerals in the paragenetic sequence.

Gibbsite Al[(OH).sub.3]

In a very rare and unusual mineral assemblage, gibbsite was found as cavity fillings in the contact zone in close association with cryolite, thomsenolite and doyleite. It occurs as dull, opaque, white to pale beige, powdery to compact globular aggregates and porcelaneous crusts in solution cavities in cellular masses consisting mostly of thomsenolite. Gibbsite and the intimately associated doyleite and thomsenolite are late-stage alteration products of cryolite. Other associated minerals are pyrrhotite, pyrite, siderite and galena. Gibbsite fluoresces intense bluish white under both shortwave and longwave ultraviolet radiation, with a strong pale yellow phosphorescence after both shortwave and longwave irradiation. The physical appearance of Saint-Amable gibbsite, its close association with cryolite and its fluorescence are very similar to those of the fluorine-bearing gibbsite described from the Saint-Michel sill (Francon quarry) by Jambor et al. (1990).

Gmelinite ([Na.sub.2], Ca)[Al.sub.2][Si.sub.4][O.sub.12] [multiplied by] 6[H.sub.2]O

Gmelinite is extremely rare in the miarolitic cavities as attractive "bow-tie" clusters of 0.8-1 mm long, colorless to white, slightly tapering hexagonal {1010} prisms terminated by the {0001} basal pinacoid. The crystals are colorless at the terminations, grading to translucent white at the base. The luster is vitreous on the prism faces and dull on the basal pinacoid. Gmelinite is one of the late-stage minerals in the paragenetic sequence.

Goethite [Alpha] - [Fe.sup.3+]O(OH)

An uncommon mineral in altered miarolitic and weathered contact-zone cavities, goethite is found as granular, reddish brown masses and crusts, and rarely as rhombic pseudomorphs, most likely after siderite.

Gypsum CaS[O.sub.4] [multiplied by] 2[H.sub.2]O

Gypsum occurs very rarely as sharp, colorless, 0.5-1 mm bladed crystals forming divergent, radiating clusters and spherical aggregates in miarolitic cavities.

Halotrichite [Fe.sub.2+][Al.sub.2][(S[O.sub.4]).sub.4] [multiplied by] 22[H.sub.2]O

An extremely rare secondary, mineral, halotrichite has been found in a sulfide-rich cavity in the contact zone as curly, opaque, white fibrous tufts 1-2 mm long on pyrite.

Hematite [Alpha]-[Fe.sub.2][O.sub.3]

Very rare in contact-zone cavities, hematite occurs as sharp, complex, tabular hexagonal crystals up to 1 mm across, and very thin black plates to 2 mm in diameter. Hematite is also found as crude, tabular, 0.5-1 mm crystals embedded in analcime around these cavities. The color is black, and deep red in thin fragments.

Hilairite [Na.sub.2]Sr[Si.sub.3][O.sub.9] [multiplied by] 3[H.sub.2]O

Hilairite, a rare silicate, was described as a new species from Mont Saint-Hilaire (Chao et al., 1974). It has also been reported from the Langesundfjord area of Norway (Raade et al., 1980), the Lovozero massif in Russia (Khomyakov and Chemitsova, 1980), the Strange Lake complex in Canada (Birkett et al., 1992), and the Pocos de Caldas complex, in Brazil (G. Y. Chao, personal communication, 1993).

Hilairite is very rare in the Saint-Amable sill, known from a small number of specimens from miarolitic cavities. It occurs as crude, opaque, pale pink, blocky crystals to 0.6-1.0 mm across, and as sharp, translucent to opaque, white, hexagonal 0.3-0.5-mm {1120} prisms terminated by the {0112} rhombohedra forming complex intergrown groups.

Hilairite is a mid to late-stage mineral in the paragenesis of the miarolitic cavities, and is associated with aegirine, natrolite, serandite, sphalerite, cordylite-(Ce) and zakharovite.

Hochelagaite (Ca, Na)[Nb.sub.4][O.sub.11] [multiplied by] 8[H.sub.2]O

Hochelagaite, the Ca-analog of franconite, was simultaneously described from the Saint-Michel sill (Francon quarry) in Montreal (type locality), and from Mont Saint-Hilaire (Jambor et al., 1986). The Saint-Amable sill is the third known locality for the mineral (Gault and Horvath, 1993). Recently, hochelagaite was also found at Vardeasen in the Langesundfjord area, Norway (Anderson et al., 1996).

Hochelagaite is exceedingly rare in the Saint-Amable sill, presently known from only a single specimen from a cavity in the contact zone. An electron microprobe (WDS) analysis gave the empirical formula: [([Ca.sub.0.87][Na.sub.0.13]).sub.[Sigma]1.00][([Nb.sub.3.81][Ti.sub.0.19][Mg.sub.0.05]).sub.[Sigma]4.05][O.sub.10.89]

[multiplied by] 8[H.sub.2]O. Hochelagaite occurs as silky, pure white, extremely thin fibers, forming radiating spherical aggregates to 1 mm in diameter. It is visually indistinguishable from franconite, and gives a weak yellowish white fluorescence under both shortwave and longwave ultraviolet radiation. Hochelagaite is a late-stage mineral in the paragenesis, associated with analcime, natrolite, catapleiite, aegirine, fluorite and dawsonite.

Jarosite [Mathematical Expression Omitted]

This secondary mineral is found very rarely as clusters of crude beige crystals less than 0.5 mm in diameter, on pyrrhotite crystals in cavities in the contact zone.

Kaolinite group

A kaolinite-group mineral similar to nacrite was tentatively identified by XRD. It occurs as powdery to fine micaceous opaque white aggregates in cavities in the contact zone.

Kukharenkoite-(Ce) [Ba.sub.2]Ce[(C[O.sub.3]).sub.3]F

Kukharenkoite-(Ce) is a new mineral simultaneously described from the Khibina massif (type locality) and the Vuorijarvi Complex, Kola Peninsula, Russia, Mont Saint-Hilaire and the Saint-Amable sill (Zaitsev et al., 1996). The mineral appears to be identical to zhonghuacerite-(Ce) which was described as a new species from the Bayan Obo rare-earth deposit in Inner Mongolia, China (Zhang and Tao, 1981). Although the name zhonghuacerite(Ce) has been well-established in the mineralogical literature (Fleischer, 1983; Fleischer and Mandarino, 1995), it appears that it has not been submitted to, nor approved by the IMA's Commission on New Minerals and Mineral Names.

The Mont Saint-Hilaire material was first found in 1986 and designated as UK65 (Chao et al., 1990); the Khibina material was at first identified as zhonghuacerite-(Ce) in 1995 (Khomyakov, 1995). The Saint-Amable material was first collected by the authors (LH and EP-H) in 1976 in the Demix quarry, but remained unidentified until 1993, when it was confirmed to be identical to MSH UK65. A microprobe (WDS) analysis of kukharenkoite-(Ce) from the Saint-Amable sill gave: BaO 50.07, CaO 0.06, SrO trace, [La.sub.2][O.sub.3] 10.27, [Ce.sub.2][O.sub.3] 14.32, [Pr.sub.2][O.sub.3] 0.37, [Nd.sub.2][O.sub.3] 1.47, F 3.14, C[O.sub.2] 21.54, O = F -1.32, total 99.91 weight %, resulting in the empirical formula: [Ba.sub.2.01] [([Ce.sub.0.54][La.sub.0.39][Nd.sub.0.05][Pr.sub.0.01][Ca.sub.0.01]).sub.[Sigma]1.00][(C[O.sub.3]).sub.3][F.sub.1.01],

based on 1([La.sup.3+] + [Ce.sup.3+] + [Pr.sup.3+] + [Nd.sup.3+] + [Ca.sup.2+]).

The mineral is extremely rare in the Saint-Amable sill, and to date only a few specimens have been positively identified. It occurs in small, 1-3 cm miarolitic cavities as colorless to very pale pinkish gray, 0.3-1 mm bladed or prismatic crystals with chisel-shaped terminations, forming oriented, most likely twinned, reticulated aggregates to 3 mm across. The reticulated and oriented crystal groups, reminiscent of reticulated cerussite, are easy to recognize and are characteristic of the mineral. Crystals are transparent grading to translucent with a vitreous to greasy luster. Some crystal groups are sprinkled with very small flakes of a white unidentified carbonate mineral.

Kukharenkoite-(Ce) is a late-stage mineral in the paragenetic sequence, associated with microcline, natrolite, eudialyte, mangan-neptunite, aegirine, rinkite, pyrite, zakharovite, yofortierite, lavenite, astrophyllite and calcite.

Labuntsovite (K,Ba,Na)(Ti,Nb)[(Si,Al).sub.2](O,OH) [multiplied by] [H.sub.2]O

Labuntsovite, the Ti end-member of the labuntsovite-nenadkevichite series (Labuntsov, 1926; Semenov and Burova, 1955; Semenov, 1959 and 1972; Golovastikov, 1974), is a relatively rare species occurring in alkaline rocks at many localities. In the Saint-Amable sill, labuntsovite is relatively common (Gault and Horvath, 1993), with small local concentrations occurring in miarolitic cavities and mineralized seams. In the fall of 1996, a large concentration of labuntsovite was found in a very unusual hornfelsized shale xenolith in the sill. The xenolith, found in situ near the sill contact, was an isolated block approximately 1 meter across, thoroughly brecciated and permeated by a dense network of narrow fractures which are lined by numerous superb, deep orange-red prismatic crystals.

Labuntsovite forms excellent, sharp, transparent, pale yellow to orange to orange-red, short to elongated prismatic crystals 0.5-3.0 mm long, having a vitreous to adamantine luster. The pale yellow crystals are generally more slender and smaller (0.5-1 mm long) than the orange and orange-red varieties. Most crystals are bounded by dominant {110} prisms and small {010) pinacoids, and are terminated by the {011} prism and a {001} basal pinacoid. Rarely, the {120} and {101} prisms have also been observed. The color of labuntsovite from most other localities is rather consistently vivid orange-red to orange-yellow, whereas in the Saint-Amable sill it varies from very pale yellow to orange to orange-red. The reason for the color variation has not been determined. The best specimens found to date are the superb deep orange-red prismatic crystals lining fissures in the xenolith mentioned above.

The difficulty of visually distinguishing elpidite from labuntsovite has already been mentioned; it is also difficult to distinguish the nearly colorless to pale yellow labuntsovite from nenadkevichite. In some cavities, all three species occur together. A reasonably good diagnostic feature is the presence of a terminating {011} prism, which tends to be well developed in labuntsovite but has not been observed in nenadkevichite. Epitactic growths of labuntsovite on elpidite have already been mentioned; the most interesting of these are short labuntsovite prisms forming epitactic caps on both ends of doubly terminated elpidite crystals.

Labuntsovite is a late-stage mineral, and in the mineralized seams it appears to be one of the products of eudialyte decomposition. The most common associated minerals are catapleiite, elpidite, cordylite-(Ce), fluorite, zakharovite, pyrrhotite, eudialyte, nenadkevichite, natrolite, microcline and aegirine.

Lavanite [(Na,Ca).sub.2]([Mn.sup.2+],[Fe.sup.2+])(Zr,Ti)[Si.sub.2][O.sub.7][(O,OH,F).sub.2]

Lavenite is relatively common in the tiny cavities that typically surround miarolitic cavities and in mineralized seams; it is common in miarolitic cavities. It occurs as translucent to opaque, beige to yellow and orange-yellow, radiating or divergent fibrous sprays and coralloidal aggregates with a greasy luster; as vitreous, transparent to translucent, thin bladed acicular crystals 1-5 mm long; and as silky, matted, yellow to brown fibrous masses 1-2 mm across, typically associated with rinkite, astrophyllite, lorenzenite, aegirine and albite. It is also found as stellate aggregates to 1 cm in diameter, densely-scattered over large surfaces (to several hundred [cm.sup.2]) in very narrow mineralized seams, especially in the southeast and southwest corners of the Demix quarry, commonly intergrown with astrophyllite and sometimes with lorenzenite. In all occurrences lavenite is one of the mid-stage minerals in the paragenesis.

Microprobe analysis (WDS) of lavenite gave the following result: [Na.sub.2]O 9.89, CaO 10.44, [K.sub.2]O trace, MnO 9.09, FeO 2.12, MgO 0.10, [Y.sub.2][O.sub.3] 0.46, [Ce.sub.2][O.sub.3] 0.38, Zr[O.sub.2] 18.28, Ti[O.sub.2] 6.79, [Nb.sub.2][O.sub.5] 5.03, Si[O.sub.2] 31.45, F 5.79, [H.sub.2]O 2.04 (calculated by stoichiometry) O = F -2.44, total 99.42 weight %, resulting in the empirical formula:]([Na.sub.1.21][Ca.sub.0.33]).sub.[Sigma]1.54][([Mn.sub.0.48][Ca.sub.0.37][Fe.sub.0.11][Y.sub.0.02][Ce.sub.0.01 ][Mg.sub.0.01]).sub.[Sigma]1.00[([Zr.sub.0.56][Ti.sub.0.32][Nb.sub.0.14]).sub.[Sigma]1.02][Si.sub.1.97][O.sub.7][[F.sub .1.15][(OH).sub.0.85]].sub.2.00], based on 9 anions. The Na values are low due to Na migration under the electron beam.

Lemoynite [(Na, K).sub.2]Ca[Zr.sub.2][Si.sub.10][O.sub.26] [multiplied by] 5-6[H.sub.2]O

Lemoynite was originally described from Mont Saint-Hilaire, Quebec (Perrault et al., 1969); the Saint-Amable sill is the second known locality for the mineral. Its occurrence is very rare, in small miarolytic cavities as sharp, vitreous, colorless, prismatic crystals forming compact, spherical aggregates 0.8-1.5 mm in diameter. Associated minerals include albite, natrolite, zakharovite, aegirine, eudialyte and polylithionite.

Lollingite Fe[As.sub.2]

Very rare in miarolitic cavities, lollingite occurs as complex groups of silvery metallic, striated, intergrown, twinned tabular crystals up to 1 mm long, associated with aegirine, mangan-neptunite, natrolite and sphalerite. The crystals are similar to and are visually difficult to distinguish from arsenopyrite.

Lorenzenite [Na.sub.2][Ti.sub.2][Si.sub.2][O.sub.9]

Lorenzenite is a relatively common species, found mostly as embedded aggregates and in narrow, mineralized seams around miarolitic cavities. Rarely it is also found as free-standing crystals in miarolitic cavities, mineralized seams and "natrolite pipes." It occurs as beige-brown to pale pinkish, thin bladed acicular crystals with pointed terminations and as aggregates of fine, fibrous crystals 0.5-3 mm long which invariably form radiating clusters and spherical aggregates 1-6 mm in diameter. The luster varies from subvitreous on the bladed crystals to silky on the fibrous crystals. Some lorenzenite fluoresces very pale yellowish white under shortwave ultraviolet radiation.

Generally, lorenzenite is one of the early minerals in the paragenesis, most frequently associated with microcline, astrophyllite, mangan-neptunite, eudialyte, aegirine, lavenite and rinkite. Lorenzenite was also found in an altered "natrolite pipe" as a very unusual, late-stage overgrowth on natrolite.

Lueshite NaNb[O.sub.3]

Lueshite, a rare perovskite-group mineral (Safiannikoff, 1959), is extremely rare and is known from only a single specimen from a miarolitic cavity. After Mont Saint-Hilaire and Lovozero, the Saint-Amable sill is the third known occurrence of the mineral in an igneous environment. Lueshite is orthorhombic but typically exhibits pseudocubic symmetry. It occurs as vitreous, translucent, brown, pseudocuboctahedra less than 0.5 mm in size which are very similar in appearance to pyrochlore. Associated minerals are eudialyte, serandite, aegirine, microcline and natrolite.

Magadiite Na[Si.sub.7][O.sub.13][(OH).sub.3] [multiplied by] 4[H.sub.2]O

Magadiite was first described from evaporite lake sediments at Lake Magadi, Kenya (Eugster, 1967), and is generally associated with alkaline brine precipitates in Oregon, California and Africa. It is rather surprising that the mineral has also been found at Mont Saint-Hilaire (Horvath and Gault, 1990), and in the Saint-Amable sill (Gault and Horvath, 1993). To our knowledge these are the only two reported localities where the mineral is associated with igneous rocks.

Magadiite is a rare, very late-stage mineral in miarolitic cavities and in hydrothermalite pods. In miarolitic cavities it occurs as compact, opaque, grayish white spheres less than 0.5 mm in diameter, with a dull, frosty, almost opalescent appearance; as silky, pale beige to white, spherical aggregates with a compact, radiating, fibrous to micaceous structure in individual spheres 0.30.5 mm in diameter; and very rarely as aggregates of sharp, colorless, equant, bipyramidal crystals 0.1-0.2 mm in diameter. Magadiite was also found in some quantity in hydrothermalite pods exposed in 1995, as opaque, white, compact powdery to fibrous masses up to 2 cm across and as silky, white, spherical aggregates and thin crusts commonly lining small cavities. Associated minerals in the hydrothermalites are: varennesite, natrolite, eudialyte, shkatulkalite, makatite, pectolite, sphalerite, monazite-(Ce), serandite, zakharovite, lorenzenite, aegirine and tuperssuatsiaite. Magadiite fluoresces yellowish white under shortwave, and a very weak white under longwave ultraviolet radiation.

XRD and microprobe analyses (EDS) also disclosed a Ca-rich variety, which may be a new Ca-analog of magadiite (Gault and Horvath, 1993), but no further investigation has been carried out.

Makatite [Na.sub.2][Si.sub.4][O.sub.8][(OH).sub.2] [multiplied by] 4[H.sub.2]O

Along with magadiite, makatite was also described as a new species from evaporites at Lake Magadi, Kenya (Sheppard et al., 1970). In recent years the mineral has been reported from a number of alkaline intrusives, including the Lovozero massif (Khomyakov et al., 1981), the Aris phonolite, Namibia (Von Knorring and Franke, 1987), Mont Saint-Hilaire (Horvath and Gault, 1990), and the Khibina massif (Khomyakov et al., 1981).

In the Saint-Amable sill makatite is relatively rare in miarolitic cavities and hydrothermalites, found mostly at the southern end of the Demix quarry. It occurs as silky, pure white to very pale green, fibrous radiating sprays to 1 cm long; as random intergrown masses up to 2 cm across; and as colorless, prismatic crystals to 1 cm long, embedded in fibrous makatite, with at least one excellent cleavage parallel to the longitudinal axis. A weak bluish white fluorescence under shortwave ultraviolet radiation has been noted. It is a late-stage mineral in the paragenesis of both modes of occurrence, typically associated with varennesite, eudialyte, zakharovite, shkatulkalite, magadiite and VUK1. It is sometimes intergrown with white, fibrous VUK1, from which it is visually indistinguishable.

Mangan-neptunite K[Na.sub.2][Li([Mn.sup.2+][Fe.sup.2+]).sub.2][Ti.sub.2][Si.sub.8][O.sub.24]

Mangan-neptunite is one of the most common species in the sill. It is most abundant in miarolitic cavities, but also common in mineralized seams, hydrothermalites and "natrolite pipes" as free-growing crystals, or embedded in the rock at the margins of cavities. It is found as superb, transparent to translucent, deep-red, opaque (almost black) tabular and prismatic crystals 1-8 mm in size. The prismatic crystals vary from the very simple, bounded by the dominant {110} prism and {001} pinacoid, with a small {100} pinacoid, to increasingly more complex crystals with additional, common and well-developed {111} positive and {111} negative prisms, and rare {210} prism. The tabular crystals exhibit all the forms noted on prismatic crystals, but are dominated by the {001} basal pinacoid. They are typically twinned, most commonly as contact twins on (001). The luster is vitreous on crystal faces and resinous on broken surfaces. Some crystals are partially hollow and show evidence of etching.

Mangan-neptunite occurs in at least two generations: as one of the early species embedded in the rock or in cavity linings overgrown by other species, and as a late-stage mineral perched on natrolite and other minerals. Although it is totally absent from cavities in the contact zone, it is associated with practically all the species found in the sill.

Marcasite Fe[S.sub.2]

Marcasite is very rare in contact-zone cavities. It is found as brassy, metallic, bladed, 1-2 mm crystals with pointed terminations.

Microcline KAl[Si.sub.3][O.sub.8]

Microcline is ubiquitous; it typically occurs as a drusy lining in miarolitic cavities and mineralized seams, and less commonly in hydrothermalites. It forms sharp, translucent to opaque, white to grayish, tabular to blocky crystals 1-10 mm across, often twinned. It is the earliest primary mineral in the paragenesis, associated with practically all other minerals found in the sill.

Microcline fluoresces dark red under shortwave ultraviolet radiation. A single microprobe analysis (WDS) of microcline gave: Si[O.sub.2] 64.58, [Al.sub.2][O.sub.3] 17.54, [K.sub.2]O 16.29, [Na.sub.2]O 0.28, SrO trace, total 98.69 weight %, resulting in the empirical formula: [([K.sub.0.97][Na.sub.0.03]).sub.[Sigma]1.00][Al.sub.0.97][Si.sub.3.02][O.sub.8], based on 8 oxygens.

Monazite-(Ce) (Ce,La,Nd,Th)P[O.sub.4]

Monazite-(Ce) is an uncommon late-stage mineral in miarolitic cavities and hydrothermalites. It is more common in miarolitic cavities, occurring as white to beige, pale brown and pale gray, parallel, lamellar aggregates forming hollow, tabular 3-8 mm crystals and relict skeletal structures with rectangular cross sections. It also forms soft, very pale bluish green, scaly, foliated aggregates; radiating groups of opaque, white, acicular crystals up to 1 mm long; and opaque, beige, thin tabular crystals forming fan-shaped groups 5-6 mm across. The tabular crystals are somewhat crude with a dull luster and appear to be pseudomorphs after an unknown mineral. They are frequently covered by a white, chalky or powdery carbonate resembling bastnasite-(Ce).

In hydrothermalites monazite-(Ce) has been found as crude, dull, opaque, gray, blocky crystals to 2 mm across. They are soft and somewhat crumbly with a.grainy texture and greasy luster, and appear to be either pseudomorphs or heavily corroded crystals.

Montmorillonite [(Na, Ca).sub.0.3][(Al, Mg).sub.2][Si.sub.4][O.sub.10][OH).sub.2] [multiplied by] n[H.sub.2]O

Powdery aggregates of montmorillonite were identified from an unspecified occurrence in the sill by A. P. Sabina (personal communication, 1993).

Muscovite K[Na.sub.2]Li[([Mn.sup.2+], [Fe.sup.2+]).sub.2][Ti.sub.2][Si.sub.8][O.sub.24]

Relatively rare in miarolitic cavities, muscovite occurs as colorless, tabular pseudohexagonal crystals up to 1 mm in diameter, and as aggregates and micaceous masses to several mm across.

Natrolite [Na.sub.2][Al.sub.2][Si.sub.3][O.sub.10] [multiplied by] 2[H.sub.2]O

Natrolite is one the most abundant minerals in the sill in all modes of occurrence, and is associated with all the other species. It is also one of the main rock-forming minerals.

In the contact-zone cavities natrolite is found as colorless, elongated, 2-15 mm prismatic crystals bounded by the {110} prism, {100} and {010} pinacoids, and terminated by {111} pyramids. Rarely, some of these crystals have a thin layer of epitactic paranatrolite on the surface, which alters to tetranatrolite on extended exposure to air.

In miarolitic cavities, natrolite is found in the following habits: colorless to white, simple prismatic crystals, 2-20 mm long; superb, colorless, short prismatic crystals of great complexity 2-6 mm long; translucent to opaque, gray, complex, somewhat crude etched crystals lining cavities, with only the crystal terminations visible; colorless crystals of a very unusual, dipyramidal habit with extremely small {110} prism, {100} and {010} pinacoids; intergrown crystalline masses filling some of the cavities; chalky to finely fibrous white masses; and as pseudomorphs most likely after nepheline and sodalite.

Intergrown, cellular masses of colorless to white prismatic crystals of natrolite also form the bulk of the infilling of the hydrothermalite pods.

The largest crystals occur in the tubular "natrolite-pipes." Colorless to translucent gray, short prismatic crystals up to 2 cm in length have been found lining the walls, commonly forming attractive, intergrown, hemispherical aggregates.

Paragenetically, natrolite is present in at least two generations: an early and a late-stage phase, in the main modes of occurrence.

Nenadkevichite Na(Nb, Ti)[Si.sub.1][O.sub.6](O, OH) [multiplied by] 2[H.sub.2]O

Nenadkevichite, the Na-Nb end-member of the labuntsovite-nenadkevichite series (Semenov, 1959), was first described from the Lovozero massif (Kuzmenko and Kazakova, 1955), and has since been reported from Mont Saint-Hilaire (Perrault et al., 1969, 1972, 1973a and 1973b), and from Ilimaussaq, Greenland (Semenov et al., 1967; Karup-Moller, 1986b). K-rich and K-dominant (K [greater than] Na) varieties of nenadkevichite have been reported from Gjerdingen, Norway (Raade and Haug, 1982), from Vuorijarvi, Kola Peninsula (Rastsvetaeva et al., 1994) and from Narssarssuk, Greenland (Petersen et al., 1996). The Saint-Amable sill is the second North American locality for the mineral (Gault and Horvath, 1993).

Nenadkevichite is relatively common in the miarolitic cavities, occurring as well-formed crystals, in tabular and prismatic habits. The less common of the two habits are colorless to transparent, very pale pink, tabular pseudohexagonal crystals, 0.5-1 mm in diameter, bounded by a dominant {001} basal pinacoid, {110} prism and {010} pinacoid. Short to elongated prisms are more common, occurring as colorless to transparent, pale yellow crystals 0.5-2.0 mm long, dominated by a {110} prism and {010} pinacoid and terminated by the {001} basal pinacoid. The luster in both habits is vitreous.

Nenadkevichite is one of the late-stage species in the paragenetic sequence, and it is associated with practically all other minerals found in the miarolitic cavities. As noted earlier, elongated prismatic crystals of nenadkevichite bear a close similarity to pale yellow labuntsovite, making it difficult to visually distinguish between the two.

The nenadkevichite-labuntsovite series (Rastsvetaeva et al., 1994; Organova et al., 1976 and 1981) exhibits marked chemical and structural variations, and according to these authors includes three chemically distinct members: an orthorhombic member represented by the Na-Nb nenadkevichite from Mont Saint-Hilaire (Perrault et al., 1969, 1972, 1973a and 1973b); a monoclinic Ti-rich member (Organova et al., 1976); and a monoclinic, K-rich nenadkevichite from Vuorijarvi (Rastsvetaeva et al., 1994). The K-dominant nenadkevichite from Narssarssuk is reported to be orthorhombic (Petersen et al., 1996).

The Saint-Amable nenadkevichite is close in composition to that reported by Perrault et al. (1969) from Mont Saint-Hilaire and is one of the closest to end-member nenadkevichite reported. Microprobe analysis (WDS) of nenadkevichite gave: [Na.sub.2]0 6.85, [K.sub.2]O 0.81, CaO trace, FeO 0.49, MnO 0.11, [Nb.sub.2][O.sub.5] 26.50, Ti[O.sub.2] 9.63, Si[O.sub.2] 39.59, [H.sub.2]O 14.84 (calculated by stoichiometry), total 98.82 weight %, resulting in the empirical formula: [(Na.sub.0.66][K.sub.0.05][Fe.sub.0.02][Mn.sub.0.01]).sub.[Sigma]0.74] [([Nb.sub.0.59][Ti.sub.0.36]).sub.[Sigma]0.95][Si.sub.1.96][O.sub.6](OH) [multiplied by] 2[H.sub.2]O, based on 9 anions. The Na value may be low due to Na migration under the electron beam. This effect in nenadkevichite is described by Petersen et al. (1996).

Nepheline (Na, K)AlSi[O.sub.4]

To date, nepheline is known only as one of the significant rock-forming minerals in the sill. Rarely, pseudomorphs of natrolite, most likely after nepheline, have been found in miarolitic cavities. They are greenish gray, short hexagonal prisms, 2-3 mm long, with basal pinacoid terminations and a greasy luster.

Opal Si[O.sub.2] [multiplied by] n[H.sub.2]O

Opal is found as a very late-stage, post-emplacement deposition in some near-surface miarolitic cavities that show signs of alteration and weathering. It occurs as mostly colorless, but very rarely pale yellow and pale blue spheres, 1-2 mm in diameter; as botryoidal aggregates; and as a thin, colorless to white, glaze-like crusts on other minerals. The luster is vitreous. It fluoresces an intense yellow-green under shortwave, and pale yellow-green under longwave ultraviolet radiation. A very weak, pale yellow phosphorescence is observed on some specimens.

Paranatrolite [Na.sub.2][Al.sub.2][Si.sub.3][O.sub.10] [multiplied by] 3[H.sub.2]O

Paranatrolite, a member of the zeolite group, was described as a new species from Mont Saint-Hilaire (Chao, 1980), where it occurs as epitactic overgrowths on natrolite. In the Saint-Amable sill it is quite rare, observed only in contact-zone cavities as a thin, colorless, visually indistinguishable epitactic layer on natrolite crystals. When exposed to air, it dehydrates to a white flaky or powdery, sometimes exfoliating layer of tetranatrolite. Fresh specimens may be preserved in water.

Pectolite Na[Ca.sub.2][Si.sub.3][O.sub.8](OH)

Pectolite is found very rarely in miarolitic cavities, as translucent to opaque, white, blocky crystals, 0.5-1 mm long, with a vitreous luster, and in a hydrothermalite pod as dull, white, divergent, fibrous sprays.

Polylithionite K[Li.sub.2]Al[Si.sub.4][O.sub.10][(F,OH).sub.2]

Polylithionite is relatively common in miarolitic cavities and hydrothermalite pods, associated with most of the species found in these. It occurs most frequently as pearly, white to pale greenish gray, foliated spherical aggregates 1-3 mm in diameter, and compact masses up to 2 cm across consisting of very fine, almost powdery, irregular flakes, 0.1-0.3 mm across. These masses often fill cavities and enclose some of the associated minerals. Rarely, it also occurs as thin, well-formed, colorless, tan to silvery gray and pale green pseudohexagonal plates up to 2 mm across, forming rosette-like aggregates. Polylithionite fluoresces a strong yellow under shortwave ultraviolet radiation, which is a reliable method of distinguishing it from other micas.

XRD and electron microprobe analysis has established that most of the mica in the sill is polylithionite. Both polylithionite-1M and polylithionite-3T polytypes have been identified from the sill, with the IM polytype being predominant. An average of five microprobe analysis gave [K.sub.2]O 12.01, [Na.sub.2]O 0.10, [Li.sub.2]O 7.41, FeO 0.47, MgO 0.09, MnO 0.13, [Al.sub.2][O.sub.3] 12.03, Si[O.sub.2] 61.30, F 8.37, [H.sub.2]O 0.56 ([Li.sub.2]O and [H.sub.2]O calculated by stoichiometry), O = F -3.52, total 98.95 weight %, resulting in the empirical formula: [([K.sub.1.02][Na.sub.0.01]).sub.[Sigma]1.03][([Li.sub.1.97][Fe.sub.0.03][Mg.sub.0.01][Mn.sub.0.01]).sub.[Sigma]2.02][A l.sub.0.94][Si.sub.4.06][O.sub.10.08][[F.sub.1.75][(OH).sub.0.25]).sub.[Sigma]2.00], based on 5([Al.sup.3+] + [Si.sup.4+]).

Pyrite Fe[S.sub.2]

Pyrite is relatively common in contact-zone cavities, but is observed only infrequently in miarolitic cavities, and as a drusy, monomineralic fracture-filling in the sill rock and in the shale underlying the sill. It occurs as bright, metallic, simple cubic crystals, rarely modified by {111} octahedra measuring 0.5-2.0 mm across, and very rarely as elongated "bars" and thin, filiform crystals.

Pyrrhotite [Fe.sub.1-x]S

Pyrrhotite is a relatively common sulfide in miarolitic and contact-zone cavities. It occurs as bronze to brassy, metallic, thin tabular hexagonal crystals, 1-4 mm across, and as rosette-like groups often with a bluish green iridescence. Thick tabular pyrrhotite crystals associated with labuntsovite were found in a hornfelsized xenolith. Pyrrhotite has also been found in mineralized seams as foil-like plates, sometimes encrusted with reddish brown goethite.

Quartz Si[O.sub.2]

Quartz is a relatively rare, late-stage mineral in miarolitic cavities, found as colorless, prismatic crystals 0.5-3 mm long. In a rare occurrence it has been observed as randomly intergrown, colorless, doubly terminated crystals 1-3 mm long, forming aggregates up to 5 cm across.

In hydrothermalites, white to pale gray chalcedony nodules having a porcelaineous luster and measuring up to 5 cm in diameter have been found embedded in natrolite and magadiite. The nodules fluoresce weak bluish white under longwave and strong greenish yellow under shortwave ultraviolet radiation, retaining weak pale yellow phosphorescence for short periods following shortwave irradiation.

Rhabdophane-(Ce) (Ce,La)P[O.sub.4] [multiplied by] [H.sub.2]O

Rhabdophane-(Ce) is an extremely rare, late-stage mineral in miarolitic and contact-zone cavities, known only from a few specimens. In contact-zone cavities it occurs as crude, dull, beige rosette-like aggregates 1.5 mm across with a somewhat powdery interior. It is similar in appearance to aggregates of donnayite-(Y) found in the same environment. Associated minerals are analcime and natrolite. In miarolitic cavities, rhabdophane-(Ce) has been found as crude, pearly, opaque, beige rectangular plates 1-2 mm across, probably pseudomorphs, associated with eudialyte, yofortierite and natrolite.

Rhodochrosite [Mn.sup.2+]C[O.sub.3]

Rhodochrosite is relatively common in miarolitic cavities, occurring as white, pale pink, orange-red, dark red and brown simple rhombs 1-8 mm across; as beige to pale pink, compact spheres, botryoidal masses and crusts; and as aggregates of pale pink, curved, "saddle-shaped" crystals up to 2 mm across encrusting cores of larger rhombs of rhodochrosite. It is also found as grains or subhedral crystals embedded in the sill rock. Rhodochrosite is associated with practically all the minerals occurring in miarolitic cavities.

Rinkite [(Ca,CE).sub.4]Na[(Na,Ca).sub.2]Ti[([Si.sub.2][O.sub.7]).sub.2][F.sub.2][(O,F).sub.2]

Rinkite is relatively common, found most frequently in mineralized seams, in tiny isolated rugs, and rarely in miarolitic cavities. It occurs as very thin, transparent to translucent, colorless to white, pale yellow and beige micaceous rectangular plates and lamellae 1-4 mm long, forming radiating, fan-like aggregates and foliated masses. In many of the tiny vugs, rinkite is the only visible mineral, frequently filling the cavities completely. Lavenite and astrophyllite are commonly associated with rinkite in the mineralized seam and small vugs.

Rinkite is a mid to late-stage species in the paragenesis of the mineralized seams and miarolitic cavities, and is associated with most species found in these.

There has been some uncertainty regarding the species status of some members of the rinkite-mosandrite series (Petersen et al., 1989). The current view (Fleischer and Mandarino, 1995) is that rinkite is a valid species, and mosandrite is an altered variety of rinkite.

Sazhinite-(Ce) analog [Na.sub.2](La, Ce)[Si.sub.6][O.sub.14](OH) [multiplied by] n[H.sub.2]O

Sazhinite-(Ce) was originally described from Mount Karnasurt, Lovozero massif, Kola Peninsula, Russia (Eskova et al., 1974; Shumyatskaya et al., 1980). The mineral has also been found at Mont Saint-Hilaire as excellent tabular crystals (Horvath and Gault, 1990). The Saint-Amable sill is the third reported locality for sazhinite (Gault and Horvath, 1993).

Sazhinite is exceedingly rare, and known from only one confirmed specimen from a small miarolitic cavity. It occurs as pearly to dull, opaque, white to pale purplish gray, rectangular, tabular crystals up to 2 mm long. On broken surfaces the mineral appears waxy and lamellar, zoned with alternating colorless and translucent to opaque, milky white zones.

Sazhinite is one of the mid-stage species in the paragenesis, and is associated with microcline, eudialyte, aegirine, serandite, yofortierite (pink), galena, natrolite and zakharovite.

A microprobe analysis (WDS) indicates that Saint-Amable sazhinite is an La-dominant analog with the following empirical formula: [([Na.sub.1.69][K.sub.0.18][Ca.sub.0.16]).sub.[Sigma]2.02][La.sub.0.44][Ce.sub.0.37][Th.sub.0.08][Nd.sub.0.05][Y.sub.0. 03][Pr.sub.0.02][U.sub.0.01]).sub.[Sigma]1.00][Si.sub.5.93][O.sub.14](OH) [multiplied by] 6[H.sub.2]O, based on 21 anions and with [H.sub.2]O calculated by stoichiometry. Lanthanum-dominant sazhinite was also reported from Mont Saint-Hilaire (Horvath and Gault, 1990) as zones in sazhinite-(Ce) crystals. The material from both localities shows patchy zoning, numerous holes and many inclusions. The currently available material is unsuitable for a full description as a new species.

Serandite Na([Mn.sup.2+], Ca).sub.2][Si.sub.3][O.sub.8](OH)

In the Saint-Amable sill, serandite is a relatively common species in miarolitic cavities, hydrothermalites and "natrolite pipes," occurring as excellent sharp crystals with a blocky to bladed habit. The blocky crystals range from opaque white to transparent or translucent, pale to intense pink and orange-pink. They are typically elongated with an approximately square to rectangular cross-section, often showing contact twinning. The largest crystals attain a length of 2.5 cm, but most are in the 2-6 mm range. The luster varies from vitreous to waxy.

The bladed habit occurs as colorless, transparent to translucent, pale pink to beige and opaque white, short to elongated crystals, with the luster varying from sub-vitreous to pearly to dull. The bladed crystals are generally smaller, 1-4 mm long, very rarely attaining 1 cm in length, and often occur in radiating, fan-like clusters.

Serandite is a mid-stage mineral in the paragenetic sequence of miarolitic cavities and hydrothermalites, with a late-stage second generation often found in miarolitic cavities. In altered miarolitic cavities it is the precursor of the birnessite pseudomorphs.

Microprobe analysis (WDS) of a colorless crystal gave: [Na.sub.2]O 8.95, MnO 23.75, CaO 10.83, FeO 1.11, Ti[O.sub.2] 0.15, Si[O.sub.2] 52.67, [Al.sub.2][O.sub.3] trace, [H.sub.2]O 2.59 (calculated by stoichiometry), total 100.09 weight %, resulting in the empirical formula: [Na.sub.1.00][([Mn.sub.1.16][Ca.sub.0.67][Fe.sub.0.05][Ti.sub.0.01].sub.[Sigma]1.89][So.sub.3.05][O.sub.8}(OH), based on 9 anions.

Shkatulkalite [Na.sub.10]Mn[Ti.sub.3][Nb.sub.3][([Si.sub.2][O.sub.7]).sub.6][(OH).sub.2]F [multiplied by] 12[H.sub.2]O

Shkatulkalite was described from the Shkatulka vein at Mount Alluaiv, Lovozero massif, Russia (Menshikov et al., 1996), where it is found as colorless, silver-white and pale pink rectangular plates and aggregates. At Saint-Amable, the only other locality for the mineral, it was found by the authors in 1995, in a very unusual hydrothermalite pod in the southeast corner of the Demix quarry, and more recently in miarolitic cavities in other parts of the quarry. In both associations it is very rare.

Shkatulkalite occurs as transparent, pale yellow to orange yellow, thin, flexible, rectangular tabular crystals and irregular plates 2-5 mm long, showing a vitreous to waxy luster and occurring in radiating aggregates 5-8 mm across. Some of the tabular crystals are well-formed and sharp, but most are characterized by rough, ragged edges, and all have numerous internal cracks. In the hydrothermalite pods most crystals are found embedded in compact masses of intergrown magadiite, natrolite and makatite, and many are bent and twisted. Shkatulkalite is visually indistinguishable from vuonnemite and epistolite.

Shkatulkalite is a mid to late-stage mineral in the paragenesis of both, miarolitic cavities and hydrothermalites. Associated minerals in the hydrothermalite are varennesite (pale and dark brown or gray and dark green), natrolite, altered eudialyte, aegirine, chalcedony nodules, sphalerite, galena, magadiite, pectolite, monazite-(Ce), lorenzenite, serandite (white sprays), calcite, pyrite, albite, opal, ancylite-(Ce), polylithionite, tuperssuatsiaite, VUK1 and VUK8. In miarolitic cavities it is associated with natrolite, analcime, eudialyte, terskite, calcite, mangan-neptunite, varennesite and zakharovite.

Siderite [Fe.sup.2+]C[O.sub.3]

Siderite is rare in miarolitic cavities and uncommon in contact-zone cavities. The crystals are simple rhombs, 0.3-1.5 mm in size, with color varying from beige to brown, and luster from vitreous to dull.

Smectite group

Two distinct minerals belonging to the smectite group have been identified by repeated X-ray diffraction analysis, but the exact species have not been determined.

Mineral A consists of compact to loose masses up to 3 cm across, of a soft, pale brown to pale orange-yellow, powdery to fine-grained mineral with a somewhat greasy luster partially filling some miarolitic cavities and "natrolite pipes." It appears to be a ubiquitous alteration product after some as yet undetermined mineral, and is almost always associated with zakharovite, from which it can be difficult to distinguish. Other closely associated species include varennesite, yofortierite, eudialyte, sphalerite and mangan-neptunite. It has also been found in very pale grayish green, bladed prismatic crystals, probably pseudomorphs, and as pale yellow-orange, very finely fibrous, sponge-like masses associated with yofortierite.

Mineral B is very rare in miarolitic cavities; it consists of thin, dark green, micaceous aggregates forming spherical masses 1-2 mm in diameter, associated with natrolite, aegirine and quartz.

Sodalite [Na.sub.8][Al.sub.6][Si.sub.6][O.sub.24][Cl.sub.2]

While characteristically abundant in agpaitic alkaline intrusions, sodalite appears to be relatively uncommon and inconspicuous in the Saint-Amable sill. It occurs as embedded colorless grains and subhedral crystals 1-4 mm in diameter disseminated in the sill rock. It fluoresces intense orange to orange-red under shortwave and less intense orange-red under longwave ultraviolet radiation, with a yellowish phosphorescence of short duration. Sodalite-enriched zones of rock in the southern end of the Demix-Varennes quarry exposed during 1994-96 contained a number of species not previously encountered in the quarry, including villiaumite, varennesite, vuonnemite, epistolite, gaidonnayite and calciohilairite.

To date, no euhedral crystals of sodalite have been found in the cavities. However, natrolite crystals with a dodecahedral morphology, which appear to be pseudomorphs after sodalite, have been observed in miarolitic cavities.

Sphalerite (Zn,Fe)S

Sphalerite is one of the most common sulfide minerals in miarolitic cavities and hydrothermalites. Rarely, it is also found in the contact-zone cavities. It occurs as excellent, sharp, lemon-yellow to orange, amber yellow, brown and black, complex, modified tetrahedra, often twinned and measuring 1-3 mm in size, and also as peculiar, elongated crystals up to 6 mm in length. The black crystals are opaque, whereas all others are transparent to translucent with vitreous to frosty or dull luster.

Strontianite SrC[O.sub.3]

Strontianite is relatively common in the contact-zone cavities, occurring as colorless, and dull white acicular crystals forming spherical aggregates up to 1 cm in diameter; as colorless capillary crystals and felted aggregates; as dull white, radiating fibrous sprays up to 5 mm long; and as colorless, elongated, pseudohexagonal prismatic crystals 1-4 mm long. It is rare in miarolitic cavities, as sharp, colorless, square to elongated tabular crystals 1-2 mm across, forming oriented and reticulated clusters and aggregates. Weak bluish white fluorescence under longwave ultraviolet radiation has been noted.

Synchysite-(Ce) Ca(Ce,La)[(C[O.sub.3]).sub.2]F

Synchysite-(Ce) is extremely rare, known from only a single, slightly altered miarolitic cavity, It occurs as sharp, opaque, beige and pale yellow to brownish yellow, tabular pseudohexagonal crystals 1-1.5 mm in diameter, forming attractive rosettes. The brownish yellow color of some crystals may be caused by iron-oxide discoloration. The luster is greasy on crystal faces and dull on broken surfaces. The crystals and crystal aggregates are very similar in appearance to, and visually indistinguishable from, those of the more common cordylite-(Ce). It is a late-stage mineral in the paragenesis, associated with microcline, astrophyllite, natrolite, eudialyte, aegirine, birnessite and opal.

Terskite [Na.sub.4]Zr[Si.sub.6][O.sub.15](OH) [multiplied by] 2[H.sub.2]O

Terskite was described as a new species from Mount Alluaiv, Lovozero massif, Kola Peninsula, Russia (Khomyakov et al., 1983), where it occurs as alteration rims on, and pseudomorphs after eudialyte. It has also been found at Mont Saint-Hilaire (Horvath and Gault, 1990) as pseudomorphs, most likely after lovozerite. The Saint-Amable sill is the third known occurrence for the species (Gault and Horvath, 1993).

Terskite is rare, found only in miarolitic cavities as dull, crude, equant, white to beige crystals resembling dodecahedra 0.6-1.0 mm in diameter. Crystal faces have a rather sugary surface texture, and some crystals are partially hollow; they are almost certainly pseudomorphs after an unknown precursor. The morphology of the crystals, and their association with fresh crystals of eudialyte almost certainly preclude eudialyte as a possible precursor. Terskite fluoresces a very weak pale yellow under shortwave ultraviolet radiation.

Terskite is clearly a late-stage mineral in the paragenesis, and is associated with eudialyte, microcline, zakharovite, aegirine, nenadkevichite, mangan-neptunite, shkatulkalite and a smectite-group mineral.

Tetranatrolite [Na.sub.2][Al.sub.2][Si.sub.3][O.sub.10][multiplied by]2[H.sub.2]O

Tetranatrolite was described as a new species from Mont Saint-Hilaire (Chen and Chao, 1980); the mineral has since been reported from numerous other localities.

Tetranatrolite is a relatively rare species in the sill, found only in some cavities in the contact-zone as powdery white layers and crusts replacing epitactic paranatrolite zones on natrolite crystals. As at Mont Saint-Hilaire, it forms as a result of dehydration of paranatrolite on exposure to air.

In recent years there has been some question as to whether gonnardite and tetranatrolite are separate species. Recent work on the natrolite group of minerals (Alberti et al., 1995) has shown that they are distinct phases, and has confirmed tetranatrolite from three localities, all in agpaitic alkaline intrusions: Mont Saint-Hilaire, Ilimaussaq and Lovozero. The tetranatrolite found at Saint-Amable has an XRD pattern identical to tetranatrolite from Mont Saint-Hilaire, but has not been evaluated by the criteria used by Alberti et al.

Thomsenolite NaCaAl[F.sub.6][multiplied by][H.sub.2]O

Thomsenolite is a relatively rare mineral, known most notably from Ivigtut, Greenland (type locality) and also from lesser-known occurrences in Colorado, Utah, Norway, Ukraine, Russia and Nigeria. At all these localities thomsenolite is associated with cryolite, as it invariably evolves as an alteration product of cryolite (Bailey, 1980). In the Saint-Amable sill thomsenolite occurs as a late-stage alteration product of cryolite, intimately associated with leached masses of cryolite and other probable cryolite decomposition products such as gibbsite and doyleite. It is very rare and to date has been found in only small quantities in the southeastern part of the Demix quarry, exposed in December 1996. Although thomsenolite has been reported from alkaline rocks, mainly alkali granites (Bailey, 1980), the Saint-Amable sill appears to be the first occurrence in agpaitic nepheline syenites. It is also the first occurrence of the mineral in Canada.

Thomsenolite was found in a very unusual mineral assemblage in the contact zone of the sill, consisting of leached cryolite and cellular masses of thomsenolite, gibbsite and doyleite. Thomsenolite forms the walls and wall linings of a dense network of small solution cavities 2-15 mm in diameter. The cavities are lined by drusy layers of thomsenolite crystals; clusters of numerous, sharp, vitreous, colorless, square tabular crystals 0.2-0.5 mm in size, project into the cavities. Crystals are bounded by the dominant {001} basal pinacoid and small {110} prisms; minor modifying faces are also present. The tabular morphology is markedly different from the well-known columnar crystals with steep pyramidal faces found at Ivigtut, but is similar to the tabular crystals reported from Miask, Ilmen Mountains, Russia (Boggild, 1913) and Gjerdingen, Oslo Region, Norway (Raade and Haug, 1980). The drusy crusts and crystal groups display the parallel crystal orientation characteristic for the mineral. An unusual feature of the Saint-Amable thomsenolite is that it fluoresces strong yellowish white under both shortwave and longwave ultraviolet radiation. Associated minerals other than those already mentioned are pyrrhotite, pyrite, galena and siderite.

Thornasite (Na,K)Th[Si.sub.11][(O,F,OH).sub.25][multiplied by]8[H.sub.2]O

Thornasite was first described from Mont Saint-Hilaire (Ansell, 1985; Ansell and Chao, 1987), where it occurs as anhedral crystals and irregular grains in an altered pegmatite. The Saint-Amable sill is the second known locality for the mineral, and the first occurrence of euhedral crystals.

Thornasite is extremely rare, having been identified from a single specimen collected in 1991 from a cavity in a large boulder quarried many years ago. The elongated cavity was approximately 10 x 10 x 50 cm in size, unusually large for the locality, and had some resemblance to a hydrothermalite. It was filled with a mass consisting almost entirely of small, intergrown, colorless natrolite crystals. In the natrolite mass are numerous interconnected cavities 2-20 mm across which are lined with superb, small, water-clear, very complex natrolite crystals. The thornasite occurred in a small cavity as a group of parallel, elongated prismatic crystals 1.5 mm long. The crystals are opaque and beige with brownish patches, with a greasy to pearly luster and smooth, well-defined faces. Broken surfaces have a chalky appearance, a patchy white to beige color, and a greasy to dull luster, and reveal unidentified black inclusions. The crystals have a hexagonal cross section and rhombohedral terminations, and may possibly be pseudomorphs. They fluoresce bluish white under shortwave ultraviolet radiation.

Thornasite is clearly a late-stage mineral in the paragenetic sequence, and closely associated only with natrolite, nenadkevichite, yofortierite, monazite-(Ce), altered eudialyte and rhodochrosite.

Titanite CaTiSi[O.sub.5]

Titanite is extremely rare, identified from only a single specimen as an embedded pale brown, short prismatic crystal.

Todorokite [Mathematical Expression Omitted]

Todorokite is rarely found in altered miarolitic cavities as thin, opaque, dark brown to black dendritic deposits and crusts.

Tuperssuatsiaite [Mathematical Expression Omitted]

Tuperssuatsiaite was original!y described from the Ilfmaussaq alkaline intrusion in South Greenland (Karup-Moller and Petersen, 1984). It has also been reported from the Aris phonolite in Namibia (Von Knorring et al., 1992), from Mont Saint-Hilaire (Wight and Chao, 1995) and the Po(/os de Caldas complex in Brazil (G. Y. Chao, personal communication,' 1995). The Saint-Amable sill is the fifth known locality for the mineral.

Tuperssuatsiaite is very rare, identified from only two specimens from a miarolitic cavity and a hydrothermalite pod. In the miarolitic cavity it occurs as short, fibrous, orange-yellow aggregates. In the hydrothermalite, it is found in small cavities in intergrown masses of natrolite, makatite and magadiite, as silky, pale brown, "paintbrush-like," finely fibrous bundles and tufts 1-2 mm long. Other associated minerals include varennesite, eudialyte, pectolite, shkatulkalite, aegirine, VUK1 and VUK9.

Tuperssuatsiaite is practically identical in appearance to and visually indistinguishable from the more common yofortierite. The X-ray powder diffraction patterns of the two species are nearly identical and generally poor and diffuse. As discussed in the section on yofortierite, the mineral from Saint-Amable sill is extremely variable in composition, however the following electron microprobe analysis (WDS) gave a formula in reasonable agreement with that of tuperssuatsiaite: [Na.sub.2]O 2.43, CaO 0.94, [K.sub.2]O 0.56, [Fe.sub.2][O.sub.3] 19.67, MnO 4.83, [Al.sub.2][O.sub.3] 1.22, MgO 0.16, Ti[O.sub.2] 0.38, Si[O.sub.2] 55.97, [H.sub.2]O 10.35 (calculated by stoichiometry) total 96.51 weight % resulting in the empirical formula: [Mathematical Expression Omitted], based 26 anions. Tuperssuatsiaite may be more common than the two identified specimens would indicate, as few attempts to analyze the yofortierite-like fibrous aggregates have been made.

Varennesite [Na.sub.8][Mn.sub.2][Si.sub.10][O.sub.25][(OH,Cl).sub.2][multiplied by]12[H.sub.2]O

Varennesite [pronounced varenn-ite with a silent s] a hydrated Na-Mn silicate, is the first new mineral species described from the Saint-Amable sill (specifically from the Demix-Varennes quarry; Grice and Gault, 1995). Although it is very rare in miarolitic cavities, high local concentrations have been encountered in a small number of peculiar, hydrothermalite pods. The type specimen was found in 1993 by one of the authors (PT) in a miarolitic cavity. Additional specimens were collected in 1994 and 1995 in hydrothermalites in the southwest and southeast corners of the Demix quarry. More recently it has been found in altered "natrolite pipes." The occurrences within the quarry may be small in number but are widespread and are separated spatially by hundreds of meters.

Varennesite is found as excellent, sharp, tabular to blocky crystals with crystals of both habits bounded by {100} and {010} pinacoids, and terminated by {101} prisms. Rarely, a small {001} basal pinacoid has also been observed on the tabular crystals. The crystals are partially translucent to opaque and the color ranges from cream-yellow to orange-yellow, deep orange, beige, pale brown, dark brown, dark green and black. Luster varies from vitreous to waxy to dull on crystal faces, and waxy to satiny to dull on cleavages and broken surfaces. The blocky crystal habit is more common, with crystals forming tightly packed, parallel aggregates 2-30 mm across. Individual crystals are 0.5-10 mm long, opaque, rarely with translucent edges and corners, and are typically doubly terminated. Crystals are usually zoned with variously altered, etched and fresh zones and some contain inclusions, such as acicular aegirine crystals. Some crystals have a fresh, vitreous outer shell and a crumbly, powdery core. Color-zoning is also common, often but not always conforming to the textural zoning, with a range of colors alternating most frequently in a concentric, and rarely in an "hourglass" pattern. Varennesite is relatively brittle, with one good cleavage along {010}, and a conchoidal fracture. Often crystals exhibit a peculiar natural cracking, sometimes exposing a dull, woody texture. Varennesite is also found as beige to pale yellow, irregular, compact, powdery to chalky masses, and as lamellar masses to several cm across. The luster is dull, except on cleavage surfaces in the lamellar masses, which have a characteristic satiny luster.

Varennesite is a very strongly alkaline late-stage mineral in miarolitic cavities, and a mid to late-stage mineral in the paragenesis of hydrothermalites. In miarolitic cavities it is associated with eudialyte, microcline, aegirine, zakharovite, mangan-neptunite, makatite, natrolite, smectite group mineral A, VUK1, VUK7, VUK8 and villiaumite. In hydrothermalites, it is associated with natrolite, magadiite, serandite, chalcedony, makatite, polylithionite, shkatulkalite, eudialyte, pectolite, lorenzenite, monazite-(Ce), VUK1, VUK9, galena, sphalerite, fluorite, dawsonite and tuperssuatsiaite.

Villiaumite NaF

Villiaumite is rare, occurring as fillings or partial fillings in small vugs, thin vein-like cavities, miarolitic cavities, in some zones of the sill characterized by dense, fine-grained, dark-colored rock particularly in the south and southeast corners exposed during 1994-96 in the Demix-Varennes quarry. The small vugs are 1-5 mm in diameter, and are typically lined by microcline with the villiaumite completely filling the cavities. In the larger miarolitic cavities, villiaumite is found exceedingly rarely as anhedral grains, infillings, and partially dissolved, crude crystals 1-2 mm across showing some crystal faces. Villiaumite is transparent and pale pink to dark carmine-red with perfect cleavage in three directions. White, sugary zones indicating partial reaching are evident in some specimens.

Paragenetically, villiaumite is a late-stage mineral found associated with microcline, lorenzenite, astrophyllite, aegirine, natrolite, eudialyte, sodalite, serandite, zakharovite, vuonnemite, makatite, varennesite and VUK1.

Vuonnemite [Na.sub.5][Nb.sub.3]Ti[([Si.sub.2][O.sub.7]).sub.3][O.sub.2][F.sub.2][multiplied by]2[Na.sub.3]P[O.sub.4]

Vuonnemite was first described from the Vuonnemi River valley, Khibina massif, Kola Peninsula, Russia as a new mineral species (Bussen et al., 1975). It has also been found in the Lovozero massif (Khomyakov et al., 1975), the Ilimaussaq complex in Greenland (Ronsbo et al., 1983) and in Mont Saint-Hilaire, Quebec (Mandarino and Anderson, 1989).

In the Saint-Amable sill, vuonnemite is very rare; it was found in miarolitic cavities in the southeast corner of the Demix pit in 1994, associated with varennesite, eudialyte, zakharovite, makatite, villiaumite and VUK1. It occurs as very thin, colorless to transparent pale yellow and opaque white, rectangular tabular crystals 1-2 mm long, dominated by the {001} pinacoid. No other forms could be indexed on the available crystals. Some of the white crystals are etched, with ragged edges and irregular perforations through the crystals. Luster varies from vitreous to greasy. The mineral fluoresces pale yellow-white under shortwave ultraviolet radiation. Vuonnemite is similar to, and may be visually indistinguishable from epistolite and shkatulkalite.

Woodruffite [Mathematical Expression Omitted]

Woodruffite was identified from a weathered miarolitic cavity collected in the Bau-Val No. 3 pit. It is very rare, occurring as black spheres up to 1 mm in diameter having a submetallic luster. Woodruffite is a late-stage mineral associated with microcline, eudialyte, mangan-neptunite, aegirine and birnessite.

Wulfenite PbMo[O.sub.4]

An extremely rare secondary mineral in miarolitic cavities, wulfenite occurs as thin, vitreous, opaque, tan to white tapering acicular crystals 0.5-0.8 mm long on galena cubes.

Yofortierite [([Mn.sup.2+],Mg).sub.5][Si.sub.8][O.sub.20][(OH).sub.2][multiplied by]8-9[H.sub.2]O

Yofortierite, the Mn-analog of palygorskite and tuperssuatsiaite, was described as a new species from Mont Saint-Hilaire (Perrault et al., 1975). The Saint-Amable sill is the second known locality for the mineral; excellent specimens have been collected in the Demix-Varennes quarry since 1976 (Gault and Horvath, 1993). More recently, yofortierite has also been reported from Mount Karnasurt, Lovozero massif, Kola Peninsula, Russia (Khomyakov, 1995).

One of the more common species in miarolitic cavities and hydrothermalites, yofortierite occurs as opaque, reddish to orange brown, dark brown, bronze-colored, pink, purple and beige capillary fibers forming tufts, divergent sprays, tightly-packed bundles, random masses and radiating spherical aggregates 5-15 mm in diameter. Individual fibers are 3-15 mm long, very thin and flexible, with a silky luster. It is visually indistinguishable from tuperssuatsiaite. For the collector, yofortierite is one of the most attractive minerals found at Saint-Amable, and the locality has yielded some of the best specimens known for the species.

Yofortierite is a mid to late-stage mineral in miarolitic cavities and hydrothermalites, and is associated with practically all the other species occurring in the sill.

Several electron microprobe analyses (WDS) indicate that some of the brownish yofortierite is an Fe-dominant (Fe [greater than] Mn) member, and may be a new species. The following analysis with resultant empirical formula is presented here, based on the formula given by Fleischer and Mandarino (1995): FeO 19.73, MgO 4.86, MnO 3.86, [Al.sub.2][O.sub.3] 2.39, CaO 1.61, Ti[O.sub.2] 0.51, [K.sub.2]O 0.06, Si[O.sub.2] 49.77, [H.sub.2]O 16.98 (calculated by stoichiometry), total 99.77 weight % resulting in the empirical formula: [Mathematical Expression Omitted]. This analysis was performed under the same operating conditions and set of standards as the analysis reported for tuperssuatsiaite. Na was sought but not detected in this analysis. Further studies are required on the chemical variations in yofortierite and tuperssuatsiaite. Ideally, structure analysis would be useful in assigning cations to various sites, however to date no suitable crystals have been found.

Zakharovite [Mathematical Expression Omitted]

Zakharovite was described simultaneously as a new mineral from Mount Karnasurt, Lovozero massif, and from Yukspor and Mount Koashva, Khibina massif, Kola Peninsula, Russia (Khomyakov et al., 1983). It had also been found in 1974 at Mont Saint-Hilaire and designated as UK38 (Chao and Baker, 1979). In the Saint-Amable sill, which is the fifth known (Gault and Horvath, 1993) and probably the richest locality for the mineral, it was first collected prior to 1976, but remained unidentified until 1991.

Zakharovite is a common and relatively abundant species in the miarolitic cavities, but relatively rare in hydrothermalites. It occurs as compact masses of bright yellow to orange to greenish yellow micaceous aggregates and scaly masses to 1 cm across. Occasionally, it is found as subhedral aggregates and crude pseudomorphs (often embedded in natrolite and replacing some unknown mineral) consisting of randomly intergrown tabular pseudohexagonal crystals less than 0.2 mm in diameter, having a layered, micaceous structure and perfect basal cleavage. Crystals are translucent to opaque with a vitreous to waxy luster.

At the type localities zakharovite is reported as a primary mineral, but in the Saint-Amable sill it is a late-stage species, and appears to be a secondary mineral associated with the alteration of eudialyte and possibly varennesite. Further studies are needed to determine the process and to pinpoint the origin of zakharovite. In miarolitic cavities the closest and most characteristic associations for the mineral are eudialyte, varennesite, catapleiite, smectite group mineral A, and labuntsovite, but practically all the other minerals occurring in these cavities, as well as in the hydrothermalites may be included as associated species.

As noted previously, zakharovite may be difficult to distinguish visually from the smectite group mineral A. A distinct scaly, rather than powdery appearance under high magnification is usually indicative of zakharovite.

Zircon ZrSi[O.sub.4]

Zircon occurs very rarely, as beige to brown, 0.5-1 mm dipyramidal crystals embedded in the light colored rock of the contact zone.

Undetermined species

In addition to descriptions of the currently undetermined (VUK) minerals, identified species with past VUK designations are also included here for reference and continuity. All the undetermined VUK minerals were first identified from specimens in the Horvath collection, and additional reference material is deposited in that collection and the collection of the Canadian Museum of Nature. X-ray data on these minerals are available on request.

VUK1

Very rare in miarolitic cavities and hydrothermalite pods, VUK1 occurs as opaque, beige and white, powdery or fibrous aggregates up to 1 cm across, most commonly associated with varennesite, zakharovite, eudialyte, makatite (sometimes intimately intergrown), shkatulkalite and mangan-neptunite. Electron microprobe (EDS) analysis shows major Si and Ti peaks, and minor Na, Ca, Th and Ce peaks.

VUK2 = Varennesite

VUK3

VUK3 is identical to the undetermined species UK51 from Mont Saint-Hilaire (Chao et al., 1990). In the Saint-Amable sill, it is found very rarely in miarolitic cavities as opaque, white, powdery aggregates 1-1.5 mm in diameter, and as crude, compact, beige spheres, less than 0.5 mm in diameter. Associated minerals are microcline, albite, aegirine and mangan-neptunite. The X-ray diffraction pattern and the chemical composition are similar to those of nordstrandite.

VUK4 = Cordylite-(Ce)

VUK5 = Calciohilairite

VUK6

Very rare, this mineral is found as sharp, pearly, opaque, white, bladed crystals and masses of irregular plates several mm across, associated with albite, microcline, mangan-neptunite, astrophyllite, zakharovite and an undetermined white powdery mineral. The X-ray powder diffraction pattern is similar to that of phillipsite. The bladed crystals are well-formed, and appear to have monoclinic or triclinic symmetry. Some of the bladed crystals fluoresce a very weak white under shortwave ultraviolet radiation.

VUK7

This mineral occurs as tan, beige and pale yellow, compact, powdery or fine micaceous masses filling interstices in miarolitic cavities. Associated minerals include eudialyte, natrolite, K-feldspar, albite, zakharovite, varennesite, mangan-neptunite and makatite. It is very similar in physical appearance to the smectite group mineral A, and to fine-grained aggregates of zakharovite. The mineral has also been identified from Mont Saint-Hilaire, where it occurs as reddish, fibrous masses, and is designated as Vogg#7 (G. Y. Chao, personal communication, 1995).

VUK8

VUK8 occurs very rarely in miarolitic cavities as random masses up to 3 mm across of silky, opaque, white fibers closely associated with makatite and varennesite. Other associated minerals are eudialyte, zakharovite, natrolite and aegirine. It is visually indistinguishable from makatite and fibrous VUK1, but exhibits weak white fluorescence under shortwave ultraviolet radiation. The XRD pattern does not match that of any known species (A. C. Roberts, personal communication, 1995).

VUK9

Very rare in miarolitic cavities and hydrothermalite pods, this mineral occurs as silky, very pale green to brownish green, somewhat matted, fibrous masses and sprays of very fine, flexible capillary crystals 2-3 mm long. It is very similar in appearance to yofortierite and tuperssuatsiaite except for the color. Associated minerals are zakharovite, eudialyte, microcline, varennesite, sphalerite, serandite and natrolite. No match has been found for the XRD powder pattern.

VUK10 = Shkatulkalite

VUK11

VUK11 was found in 1995 in the southeast corner of the Demix quarry in small miarolitic cavities associated with natrolite, aegirine, albite, mangan-neptunite, rhodochrosite, sphalerite, astrophyllite and a beige to brown unidentified mineral. It occurs as thin, pearly, silvery white, flexible, rounded to irregular micaceous plates 0.3- 0.5 mm in diameter forming spherical and rosette-like aggregates.

The XRD pattern and physical appearance are nearly identical to those of the undetermined Mont Saint-Hilaire mineral designated as UK60, a carbonate of Sr, Ba, Ca and REE (Chao et al., 1990). Microprobe analysis (EDS) of VUK11 indicates major Ca but no Ba or Sr. based on the available data, it appears to be the Ca analog of UK60, and a possible new species.

VUK12 = Kukharenkoite-(Ce)

ACCESS

In recent years the owner of the Demix-Varennes quarry, Demix Agregats, has granted mineral clubs permission for weekend field trips if they are covered by suitable liability insurance. A fee is charged to cover the additional cost of security. Arrangements must be made through the company's head office in Longeuil, Quebec.

ACKNOWLEDGMENTS

We are very grateful for the generous assistance of the following individuals: Dr. George Chao and Ronald Conlon of Carleton University, Ottawa; Jerry Van Velthuizen of the Research Division, Canadian Museum of Nature; Andrew Roberts of the Geological Survey of Canada; Malcolm Back of the Royal Ontario Museum, for X-ray powder diffraction analyses; Dr. Andrew McDonald of Laurentian University, Sudbury, Ontario, for the whole-rock analyses; Ann Sabina of the Geological Survey of Canada, for information on some of the minerals; Dr. Brian Down for the SEM photography; Dr. Peter Richards for assistance with the natrolite morphology; Dr. Pete Dunn of the Smithsonian Institution and Dr. Donald Peacor of the University of Michigan for reviewing the manuscript and making many suggestions to improve the paper; Dr. Wendell Wilson for editorial guidance; and Robert Rothenberg, Robin Tibbit and Walter Lane for sharing collecting information and specimens. On behalf of the collecting community, we wish to express our appreciation to the management of Demix Agregats, owners of the Demix-Varennes quarry, for allowing access to their quarry, in support of this research project.

BIBLIOGRAPHY

ADAMS, F. D. (1903) The Monteregian Hills - a Canadian petrographical province. Journal of Geology, 11, 239-282.

ALBERTI, A., CRUCIANI, G., and DAURU, I. (1995) Order-disorder in natrolite-group minerals. European Journal of Mineralogy, 7, 501-508.

ALLEN, J. B., and CHARSLEY, T. J. (1968) Nepheline-syenite and Phonolite. Institute of Geological Sciences Publication, London, 160 p.

ANDERSEN, F., BERGE, S. A., and BURVALD, I. (1996) Die Mineralien des Langesundsfjords und des umgebenden Larvikit-Gebietes, Oslo-Region, Norwegen. Mineralien Welt, 7, No. 4, 21-100 (in German).

ANSELL, V. E. (1985) A study of UK27, a new thorium mineral, with remarks on the mineralogy and igneous behaviour of thorium. Unpublished M.Sc. Thesis, Carleton University, Ottawa.

ANSELL, V. E., and CHAO, G. Y. (1987) Thornasite, a new hydrous sodium thorium silicate from Mont St-Hilaire, Quebec. Canadian Mineralogist, 25, 181-183.

BAILEY, J. C. (1980) Formation of cryolite and other aluminofluorides: A petrologic review. Bulletin of the Geological Society of Denmark, 29, 1-45.

BIRKETT, T. C., MILLER, R. R., ROBERTS, A. C., and MARIANO, A. N. (1992) Zirconium-bearing minerals from the Strange Lake intrusive complex, Quebec-Labrador. Canadian Mineralogist, 30, 191-205.

BOGGILD, O. B. (1913) Beobachtungen uber die Mineralien der Kryolithgruppe. Zeitschrift fur Krystallographie, 51, 591-613 (in German).

BOGGILD, O. B., and WINTHER, C. (1901) On some minerals from the nepheline syenite at Julianehaab, Greenland (epistolite, britholite, schizolite and steenstrupine). Meddelelser om Gronland, 24, 181-213.

BOGGS, R. C. (1988) Calciohilairite; CaZr[Si.sub.3][O.sub.9][multiplied by]3[H.sub.2]O, the calcium analogue of hilairite from the Golden Horn batholith, northern Cascades, Washington. American Mineralogist, 73, 1191-1194.

BUSSEN, I. V., DENISOV, A. P., ZABAVNIKOVA, N. I., KOZYREVA, L. V., MENSHIKOV, Yu. P., and LIPATOVA, E. A. (1975) Vuonnemite, a new mineral. International Geology Review, 17, No. 3, 354-357.

CANNILLO, E., ROSSI, G., and UNGARETTI, L. (1973) The crystal structure of elpidite. American Mineralogist, 58, 106- 109.

CHAO, G. Y. (1980) Paranatrolite, a new zeolite from Mont St-Hilaire, Quebec. Canadian Mineralogist, 18, 85-88.

CHAO, G. Y. (1985) The crystal structure of gaidonnayite [Na.sub.2]Zr[Si.sub.3][O.sub.9][multiplied by]2[H.sub.2]O. Canadian Mineralogist, 23, 11-15.

CHAO, G. Y., and BAKER, J. (1979) What's new from Mont St. Hilaire, Quebec. Mineralogical Record, 10, 99-101.

CHAO, G. Y., BAKER, J., SABINA, A. P., and ROBERTS, A. C. (1985) Doyleite, a new polymorph of Al[(OH).sub.3], and its relationship to bayerite, gibbsite and nordstrandite. Canadian Mineralogist, 23, 21-28.

CHAO, G. Y., CONLON, R. P., and VAN VELTHUIZEN, J. (1990) Mont Saint-Hilaire unknowns. Mineralogical Record, 21, 363- 368.

CHAO, G. Y., MAINWARING, P. R., and BAKER, J. (1978) Donnayite, NaCa[Sr.sub.3]Y[(C[O.sub.3]).sub.6[multiplied by]3[H.sub.2]O, a new mineral from Mont St-Hilaire, Quebec. Canadian Mineralogist, 16, 335-340.

CHAO, G. Y., ROWLAND, J. R., and CHEN, T. T. (1973) The crystal structure of catapleiite. Geological Society of America Abstracts, 5, 572.

CHAO, G. Y., and WATKINSON, D. H. (1974) Gaidonnayite, [Na.sub.2]Zr[Si.sub.3][O.sub.9][multiplied by]2[H.sub.2]O, a new mineral from Mont St. Hilaire, Quebec. Canadian Mineralogist, 12, 316-319.

CHAO, G. Y., WATKINSON, D. H., and CHEN, T. T. (1974) Hilairite, [Na.sub.2]Zr[Si.sub.3][O.sub.9][multiplied by]3[H.sub.2]O, a new mineral from Mont St. Hilaire, Quebec. Canadian Mineralogist, 12, 237-240.

CHEN, T. T., and CHAO, G. Y. (1973) Twinning in catapleiite. Geological Society of America Abstracts, 5, 573-574.

CHEN, T. T., and CHAO, G. Y. (1975) Cordylite from Mont St. Hilaire, Quebec. Canadian Mineralogist, 13, 93-94.

CHEN, T. T., and CHAO, G. Y. (1980) Tetranatrolite from Mont St- Hilaire, Quebec. Canadian Mineralogist, 18, 77-84.

CLARK, T. H. (1943) Preliminary report on the St. Jean and Beloeil map areas. Quebec Department of Mines, Geological Surveys Branch, Preliminary Report, No. 177.

CLARK, T. H. (1955) St. Jean - Beloeil area. Quebec Department of Mines, Geological Report, No. 66.

CLARK, T. H. (1972) Montreal area. Ministere des Richesses Naturelles de Quebec, Geological Exploration Service, Geological Report, No. 152.

CURRIE, K. L. (1970) An hypothesis on the origin of alkaline rocks suggested by the tectonic setting of the Monteregian Hills. Canadian Mineralogist, 10, 411-420.

CURRIE, K. L. (1976) The Alkaline Rocks of Canada. Geological Survey of Canada, Bulletin 239, 207-209.

CZAMANSKE, G. K., LEONARD, B. F., and CLARK, J. R. (1980) Erdite, a new hydrated sodium iron sulfide mineral. American Mineralogist, 65, 509-515.

DAL NEGRO, A., ROSSI, G., and TAZZOLI, V. (1975) The crystal structure of ancylite, [(RE).sub.x][(Ca,Sr).sub.2-x][(C[O.sub.3]).sub.2][(OH).sub.x](2-x)[H.sub.2]O. American Mineralogist, 60, 280-284.

DRESSER, J. A. (1910) Geology of St. Bruno Mountain. Geological Survey of Canada Memoir No. 7, 33 p.

DRESSER, J. A., and DENIS, T. C. (1944) Geology of Quebec. Vol. II, 469-470, Province of Quebec, Canada, Department of Mines, Geological Report 20.

DOIG, R., and BARTON, J. M. (1968) Ages of carbonatites and other alkaline rocks in Quebec. Canadian Journal of Earth Sciences, 8, 1401-1407.

DONNAY, G., and DONNAY, J. D. H. (1955) Cordylite reexamined. Bulletin Geological Society of America, 66, 1551.

EBY, G. N. (1984) Geochronology of the Monteregian Hills alkaline igneous province, Quebec. Geology, 12, 468-470.

ERCIT, T. S., and HAWTHORNE, F. C. (1987) The crystal structure of vuonnemite, a [Ti.sup.3+]-bearing phosphate-silicate mineral. Program with Abstracts, Geological Association of Canada; Mineralogical Association of Canada; Canadian Geophysical Union, Joint Annual Meeting, 12, 41.

ESKOVA, E. M., SEMENOV, E. I., KHOMYAKOV, A. P., KAZAKOVA, M. E., and SHUMYATSKAYA, N. G. (1974) Sazhinite, a new silicate of sodium and rare earths. Zapiski Vsesoyuznogo Mineralogicheskogo Obshestva, 103, 338-341 (in Russian). English abstract: American Mineralogist, 60, (1975), 162.

EUGSTER, H. (1967) Hydrous sodium silicates from Lake Magadi, Kenya: Precursors of bedded chert. Science, 157, 1177-1180.

FAIRBAIRN, H. W., FAVRE, G., PINSON, W. H., HURLEY, P. M., and POWELL, J. L. (1963) Whole-rock age, and discordant biotite in the Monteregian igneous province, Quebec. Journal of Geophysical Research, 68, 6515-6522.

FERGUSON, R. B. (1946) On the crystallography of thomsenolite and pachnolite. Transactions of the Royal Society of Canada, 40, Part IV, 11-25.

FLEISCHER, M. (1983) Glossary of Mineral Species. Mineralogical Record Inc., Tucson, 202 p.

FLEISCHER, M., and MANDARINO, J. A. (1995) Glossary of Mineral Species. Mineralogical Record Inc., Tucson, 280 p.

FLINK, G. (1901) On the minerals from Narsarsuk on the Firth of Tunugdliarfik in Southern Greenland. Meddelelser om Gronland, 24, 42-49.

FOLAND, K. A., GILBERT, L. A., SEBRING, C. A., and CHEN, J. F. (1986) 40Ar/30Ar ages for plutons of the Monteregian Hills, Quebec: evidence for a single episode of Cretaceous magmatism. Geological Society of America Bulletin, 97, 966-974.

FU, PINGQIU, and KONG, YOUHUA (1987) The crystal structure of baiyuneboite-(Ce). Acta Mineralogica Sinica, 7, No. 4, 298-304 (in Chinese, with English abstract). Abstracted in American Mineralogist, 75, 240.

FU, PINGQIU, and SU, XIANZE (1988) Baiyuneboite-(Ce) - a new mineral. Chinese Journal of Geochemistry, 7, 348-356 (in Chinese, with English abstract). Abstracted in American Mineralogist, 75, 240.

GALLI, E., and ALBERTI, A. (1971) Crystal structure of rinkite. Acta Crystallographica, B27, 1277-1284.

GAULT, R. A., and HORVATH, L. (1993) Preliminary report on the mineralogy of the Saint-Amable sill, Varennes, Quebec. Program with abstracts, 20th Rochester Mineralogical Symposium, April 1993, 8-9. Abstracted in Rocks and Minerals, 69, 116.

GERASIMOVSKY, V. I. (1956) Geochemistry and mineralogy of nepheline syenite intrusions. Geochemistry, (1956), No. 5,494- 510.

GERASIMOVSKY, V. I. (1963) Geochemical features of agpaitic nepheline syenites. In Chemistry of the Earth's Crust. Vinogradov, A. P., editor (published in Russian). English translation published by Israel Program for Scientific Translations.

GIUSEPPETTI, G., MAZZI, F., and TADINI, C. (1971) The crystal structure of eudialyte. TMPM Tschermaks Mineralogische und Petrologische Mitteilungen, 16, 105-127.

GLOBENSKY, Y. (1985) Geologie des regions de Saint-Jean (partie nord) et de Beloeil. Ministere de l'Energie et des Ressources, Direction general de l'Exploration geologique et minerale, Gouvernement du Quebec, MM 84-03, 97 p. and 2 maps (in French).

GOLD, D. P. (1979) Alkaline ultrabasic rocks in the Montreal area, Quebec. In Ultramafic and Related Rocks, Wyllie, P. J., editor. 288-302. Robert E. Krieger Publ. Co.

GOLOVASTIKOV, N. I. (1974) Crystal structure of the alkali titanosilicate labuntsovite. Soviet Physics, Crystallography, 18, No. 5, 596-599.

GOLYSHEV, V. M., SIMONOV, V. I., and BELOV, N. V. (1971) Crystal structure of eudialyte. Soviet Physics, Crystallography, 16, No. 1, 70-74.

GRAHAM, R. P. D. (1908) Dawsonite: A Carbonate of Soda and Alumina. Transactions of the Royal Society of Canada, Series III, Section IV, 165-177.

GRICE, J. D., and GAULT, R. A. (1995) Varennesite, a new species of hydrated Na-Mn silicate with a unique monophyllosilicate structure. Canadian Mineralogist, 33, 1073-1081.

HANES, F. E. (1962) Physical tests and petrographic analysis of crushed stone from the Varennes Quarry Ltd., Vercheres, P.Q. Canada Department of Mines and Technical Surveys, Mines Branch, Mineral Processing Division, Test Report, MPT-62-3, 5 p.

HARRINGTON, B. J. (1875) Notes on Dawsonite, a new carbonate. The Canadian Naturalist and Quarterly Journal of Science, VII, 305-309.

HARRINGTON, B. J. (1878) Note on the composition of dawsonite. The Canadian Naturalist, New series, X, 84-86.

HODGSON, C. J. (1969) Monteregian Dike Rocks. Unpublished Ph.D. thesis, Department of Geology, McGill University, Montreal, Quebec. 168 p.

HORVATH, L., and GAULT, R. G. (1990) The mineralogy of Mont Saint-Hilaire. Mineralogical Record, 21, 284-359.

HO-TUN, E. (1970) Studies on eudialyte and eucolite. Unpublished M.Sc. Thesis, Carleton University, Ottawa. 115 p.

ILYUSHIN, G. D., VORONKOV, A. A., NEVSKY, N. N., ILYUKIN, V. V., and BELOV, N. V. (1981) Crystal structure of hilairite, [Na.sub.2]Zr[Si.sub.3][O.sub.9][multiplied by]3[H.sub.2]O. Soviet Physics, Doklady, 26, 916-917.

JAMBOR, J. L., SABINA, A. P., RAMIK, R. A., and STURMAN, B. D. (1990) Fluorine-bearing gibbsite-like mineral from the Francon Quarry, Montreal, Quebec. Canadian Mineralogist, 28, 147-153.

JAMBOR, J. L., SABINA, A. P., ROBERTS, A. C., BONARDI, M., RAMIK, R. A., and STURMAN, B. D. (1984) Franconite, a new hydrated Na-Nb oxide mineral from Montreal Island, Quebec. Canadian Mineralogist, 22, 239-243.

JAMBOR, J. L., SABINA, A. P., ROBERTS, A. C., BONARDI, M., OWENS, D. R., and STURMAN, B. D. (1986) Hochelagaite, a new calcium-niobium oxide mineral from Montreal, Quebec. Canadian Mineralogist, 24, 449-453.

JONES, L. H. P., and MILNE, A. A. (1956) Birnessite, a new manganese oxide mineral from Aberdeenshire, Scotland. Mineralogical Magazine, 31, 283-288.

JOHNSEN, O., and GAULT, R. A. (1997) Chemical variation in eudialyte. Neues Jahrbuch fur Mineralogie, Abhandlungen, 171, 215-237.

KARUP-MOLLER, S. (1986a) Epistolite from the Ilimaussaq alkaline complex in South Greenland. Neues Jahrbuch fur Mineralogie, Abhandlungen, 155, 289-304.

KARUP-MOLLER, S. (1986b) Nenadkevichite from the Ilimaussaq intrusion in South Greenland. Neues Jahrbuch fur Mineralogie, Monatshefte, Jg. 1986, 49-58.

KARUP-MOLLER, S., and PETERSEN, O. V. (1984) Tuperssuatsiaite, a new mineral species from the Ilimaussaq intrusion in South Greenland. Neues Jahrbuch fur Mineralogie, Monatshefte, Jg. 1984, 501-512.

KHEIROV, M. B., MAMEDOV, K. S., and BELOV, N. V. (1963) The structure of rinkite, Na[(Ca,Ce).sub.2](Ti,Ce)O[[Si.sub.2][O.sub.7]]F. Doklady Akademii Nauk SSSR, Earth Sciences Section, 150, No. 1, 103- 106.

KHOMYAKOV, A. P. (1990) Mineralogy of Hyperagpaitic Alkaline Rocks. Nauka, Moscow, 196 p. (in Russian). KHOMYAKOV, A. P. (1995) Mineralogy of Hyperagpaitic Alkaline Rocks. Oxford University Press, Oxford, 223 p. Revised and updated version of the Russian original, published in 1990 by Nauka, Moscow.

KHOMYAKOV, A. P., and CHERNITSOVA, N. M. (1980) Hilairite, [Na.sub.2]Zr[Si.sub.3][O.sub.9][multiplied by]3[H.sub.2]O - first find in the USSR. Mineralogicheskii Zhurnal, 2, No. 3, 95-96.

KHOMYAKOV, A. P., KAZAKOVA, M. E., VRUBLEVSKAYA, Z. V., ZVYAGIN, B. B., and PILOYAN, G. O. (1983) Zakharovite, [Mathematical Expression Omitted], a new hydrous silicate of sodium and manganese. International Geology Review, 25, 978-982.

KHOMYAKOV, A. P., KOROBITSYN, M. F., DOBROVOLSKAYA, M. G., and TSEPIN, A. I. (1982) Erdite NaFe[S.sub.2][multiplied by]2[H.sub.2]O, first find in the USSR. Doklady Akademii Nauk SSSR, Earth Sciences Section, 249, No. 4, 161-163.

KHOMYAKOV, A. P., SEMENOV, E. I., ESKOVA, E. M., KAZAKOVA, M. E., SHUMYATSKAYA, N. G., and RUDNITSKAYA, E. S. (1975) Vuonnemite from Lovozero. Izvestiya Akademii Nauk SSSR, Seriya Geologicheskaya, 8, 78-87 (in Russian).

KHOMYAKOV, A. P., SEMENOV, E. I., VORONIKOV, A. A., and NECHELLYUSTOV, G. N. (1983) Terskite, [Na.sub.4]Zr[Si.sub.6][O.sub.16][multiplied by][H.sub.2]O, a new mineral. International Geology Review, 25, 1162-1167.

KHOMYAKOV, A. P., STEPANOV, V. I., BYKOVA, and NAUMOVA, I. S. (1981) Makatite, [Na.sub.2][Si.sub.4][O.sub.9][multiplied by]5[H.sub.2]O, first find in the USSR. Doklady Akademii Nauk SSSR, Earth Sciences Section, 255, 181-185.

KIM, S. J. (1980) Birnessite and rancieite problem: their crystal chemistry and new classification. Journal of the Geological Society of Korea, 16, 105-113. Abstract: American Mineralogist, 69, (1984), 814.

KOGARKO, L. N., and ROMANCHEV, B. P. (1976) Physiochemical conditions of deposition of eudialyte mineralization in agpaitic nepheline syenite. Doklady Akademii Nauk SSSR, Earth Sciences Section, 229, 179-181.

KUMARAPELI, P. S. (1970) Monteregian alkalic magmatism and the St. Lawrence rift system in space and time. In Alkali Rocks: The Monteregian Hills. Perrault, G., editor. Published by Mineralogical Association of Canada.

KUZMENKO, M. V., and KAZAKOVA, M. E. (1955) Nenadkevichite - a new mineral. Doklady Akademii Nauk SSSR, 100, 1159-1160 (in Russian). English abstract: American Mineralogist, 40, 1154.

LABUNTSOV, A. N. (1926) Titaniferous elpidite from Mount Chibina, Russian Lapland, and its paragenesis. Doklady Akadmii Nauk SSSR, Seriya A (March), 39-42 (in Russian). English abstract: American Mineralogist, 12, 295-296.

LE MAITRE, R. W. (1976) The chemical variability of some common igneous rocks. Journal of Petrology, 17, 589-637.

MANDARINO, J. A., and ANDERSON, V. (1989) Monteregian Treasures: The Minerals of Mont Saint-Hilaire, Quebec. Cambridge University Press, New York, 281 p.

MARSH, B. D. (1996) Solidification fronts and magmatic evolution. Mineralogical Magazine, 60, 5-40.

MELLINI, M. (1981) Refinement of the crystal structure of lavenite. TMPM Tschermaks Mineralogische und Petrographische Mitteilungen, 28, 99-112.

MENSHIKOV, Yu. P., KHOMYAKOV, A. P., POLEZHAEVA, L. I., and RASTSVETAEVA, R. K. (1996) Shkatulkalite, [Na.sub.10]Mn[Ti.sub.3][Nb.sub.3][([Si.sub.2][O.sub.7]).sub.6][(OH).sub.2]F[multiplied by]12[H.sub.2]O - a new mineral. Zapiski Vserossiiskogo Mineralogicheskogo Obshchestva, 1996, No. 1, 120-126 (in Russian).

MIKHEEVA, M. G., PUSHCHAROVSKY, D. Yu., KHOMYAKOV, A. P., and YAMNOVA, N. A. (1986) Crystal structure of tetranatrolite. Soviet Physics, Crystallography, 31, (3), 254-257.

NIKANDROV, S. N. (1989) Franconite - first find in the USSR. Doklady Akademii Nauk SSSR, 305, No. 3. 700-703 (in Russian).

OFTEDAL, I. (1931) Uber Parisit, Synchysit and Kordylit. Zeitschrift fur Kristallographie, 79, 437-464 (in German).

ORGANOVA, N. I., SHLUKOVA, Z. V., ZABAVNIKOVA, N. I., PLATONOV, A. N., and RUDNITSKAYA, E. S. (1976) Crystal chemistry of labuntsovite and nenadkevichite. Izvestiya Akademii Nauk SSSR, Seriya Geologicheskaya, 1976, No. 6, 98-116 (in Russian).

ORGANOVA, N. I., ARCHIPENKO, D. K., DIKOV, Yu. P., KARPINSKY, O. G., and SHLUKOVA, Z. V. (1981) Structural peculiarities of new potassium substituted variety of labuntsovite and its position in the labuntsovite-nenadkevichite family. Mineralogicheski Zhurnal, 3, No. 2, 49-63 (in Russian).

PERRAULT, G. (1972) Contribution a l'etude de la serie nenadkevichite [(Nb,Ti)(Na,Ca)[Si.sub.2][O.sub.7][multiplied by]2[H.sub.2]O] - labuntsovite [(Ti,Nb)(K,Ba)[Si.sub.2][O.sub.7][multiplied by]2[H.sub.2]O]. Program with abstracts, 24th Geological Congress, Montreal, 427 (in French).

PERRAULT, G., BOUCHER, C., VICAT, J., CANNILLO, E., and ROSSI, G. (1973a) Structure cristalline de nenadkevichite [(Na,K).sub.2-x](Nb,Ti)(O,OH)([Si.sub.2][O.sub.6])[multiplied by]2[H.sub.2]O. Acta Crystallographica, B29, 1432-1438 (in French).

PERRAULT, G., BOUCHER, C., VICAT, J., CANNILLO, E., and ROSSI, G. (1973b) Nenadkevichite, [(Na,K).sub.2-x][(Nb,Ti).sub.2][(O,OH).sub.4]- [Si.sub.4][O.sub.12][multiplied by]4[H.sub.2]O, a new four-fold silica tetrahedra ring structure. American Mineralogist, 58, 1102-1103 (abstract).

PERRAULT, G., HARVEY, Y., and PERTSOWSKY, R. (1975) La yofortierite, un nouveau silicate hydrate de manganese de St- Hilaire, P.Q. Canadian Mineralogist, 13, 68-74 (in French with English abstract).

PERRAULT, G., SEMENOV, E. I., BIKOVA, A.V., and CAPITONOVA, T. A. (1969) La lemoynite, un nouveau silicate hydrate de zirconium et de sodium de St-Hilaire, Quebec. Canadian Mineralogist, 9, 585-596 (in French with English abstract).

PERRAULT, G., VICAT, J., and SANG, N. (1969) UK-19-1 et UK- 19-2, [nenadkevichite] deux nouveau silicates hydrates de niobium du Mont St-Hilaire, P.Q. Canadian Mineralogist, 10, 143- 144 (abstract) (in French).

PETERSEN, O. V., GAULT, R. A., and LEONARDSEN, E. S. (1996) A K-dominant nenadkevichite from the Narssarssuk pegmatite, South Greenland. Neues Jahrbuch fur Mineralogie, Monatshefte, Jg. 1996, (3), 103-113.

PETERSEN, O. V., RONSBO, J. G., and LEONARDSEN, E. S. (1989) Nacareniobsite-(Ce), a new mineral species from the Ilimaussaq alkaline complex, South Greenland, and its relation to mosandrite and the rinkite series. Neues Jahrbuch fur Mineralogie, Monatshefte, Jg. 1989, (2), 84-96.

PHILPOTTS, A. R. (1970) Mechanism of emplacement of the Monteregian intrusion. In Alkali Rocks: The Monteregian Hills. Perrault, G., editor. Published by: Mineralogical Association of Canada.

PHILPOTTS, A.R. (1976) Petrography of Mounts Saint-Bruno and Rougemont. Ministere des Richesses Naturelles du Quebec, Direction Generale des Mines, Memoir ES-16, 52 p.

RAADE, G., and HAUG, J. (1980) Rare fluorides from a soda granite in the Oslo Region, Norway. Mineralogical Record, 11, 83-91.

RAADE, G., and HAUG, J. (1982) Gjerdingen Fundstelle seltener Mineralien in Norwegen. Lapis, 7, (6), 9-15 (in German).

RAADE, G., HAUG, J., KRISTIANSEN, R., and LARSEN, A. O. (1980) Langesundfjord. Lapis, 5, (10), 22-28 (in German).

RASTSVETAEVA, R. K., TAMAZYAN, R. A., PUSHCHAROVSKY, D. Yu., and NADEZHINA, T. N. (1994) Crystal structure and microtwinning of K-rich nenadkevichite. European Journal of Mineralogy, 6, 503-509.

RONSBO, J. G., LEONARDSEN, E. S., PETERSEN, O. V., and JOHNSEN, O. (1983) Second occurrence of vuonnemite: the Ilimaussaq alkaline intrusion, South West Greenland. Neues Jahrbuch fur Mineralogie, Monatshefte, Jg. 1983, (10), 451- 460.

SABINA, A. P. (1978) Minerals of the Francon Quarry (Montreal Island): a progress report. Geological Survey of Canada, Paper 79-1A, 115-120.

SAFIANNIKOFF, A. (1959) Un nouveau mineral de niobium. (lueshite) Bulletin, Academie Royale Scientifique d'outre-mer (Belgium), 5, 1251-1255 (in French). English abstract: American Mineralogist, 46, 1004.

SAHAMA, Th. G. (1947) Analysis of ramseyite and lorenzenite. American Mineralogist, 32, 59-63.

SCHALLER, W. T. (1955) The pectolite - schizolite - serandite series. American Mineralogist, 40, 1022-1031.

SEMENOV, E. I. (1959) Labuntsovite - Nenadkevichite Isomorphous Series. Trudy IMGRE Doklady Akademii Nauk SSSR, No. 2, 102-109 (in Russian).

SEMENOV, E. I. (1972) Mineralogy of the Lovozero Alkaline Massif. Published by "NAUKA" Moscow, 307 p. (in Russian).

SEMENOV, E. I., and BUROVA, T. A. (1955) On the new mineral, labuntsovite, and the so-called titanoelpidite. Doklady Akademii Nauk SSSR, 101, 1113-1116 (in Russian). English abstract: American Mineralogist, 41, 163.

SEMENOV, E. I., KAZAKOVA, M. E., and ALEKSANDROVA, R. A. (1967) The Lovozero minerals - nenadkevichite, gerassimovskite and tundrite - from Ilimaussaq, South Greenland. Meddelelser om Gronland, 181, 1-11.

SEMENOV, E. I., ORGANOVA, N. I., and KUKHARCHIK, N. V. (1961) New data on minerals of the lomonosovite-murmanite group. Kristallografiya, 6, (6), 926-932 (in Russian).

SHEN, JINCHUAN, and MI, JINXIAO (1992a) New data on cordylite-(Ce). Acta Petrologica et Mineralogica (China), 11, 69-74 (in Chinese with English abstract).

SHEN, JINCHUAN, and MI, JINXIAO (1992b) New advances in structural studies of barium rare-earth fluorcarbonate minerals. Journal of China University Geosciences, 3, 17-24.

SHEPPARD, R. A., GUDE, A. J., and HAY, R. L. (1970) Makatite, a new hydrous sodium silicate mineral from Lake Magadi, Kenya. American Mineralogist, 55, 358-366.

SHUMYATSKAYA, N. G., VORONKOV, A. A., and PYATENKO, Ya. A. (1980) Sazhinite, [Na.sub.2]Ce[[Si.sub.6][O.sub.14](OH)][multiplied by]n[H.sub.2]O: a new representative of the dalyite family in crystal chemistry. Soviet Physics, Crystallography, 25, (44), 419-423.

SORENSEN, H. (1960) On the agpaitic rocks. Proceedings of the International Geological Congress, 21st Session, Norden, Part 13, 319-327.

SORENSEN, H., ed. (1974) The Alkaline Rocks. John Wiley & Sons, New York, 622 p.

SUNDBERG, M. R., LEHTINEN, M., and KIVEKAS, R. (1987) Refinement of the crystal structure of ramsayite (lorenzenite). American Mineralogist, 72, 173-177.

SZYMANSKY, J. T., and CHAO, G. Y. (1986) The crystal structure of monoclinic ancylite. Program with abstracts, Annual Meeting of the American Crystallographic Association. Hamilton (Canada) June 22-27, 1986.

TAKEUCHI, Y., KUDOH, Y., and YAMANAKA, T. (1976) Crystal chemistry of the serandite - pectolite series and related minerals. American Mineralogist, 61, 229-237.

TELFORD, W. M., GELDART, L. P., SHERIFF, R. E., and KEYS, D. A. (1976) In: Applied Geophysics, Cambridge University Press, 195-197.

TRINH, T. L. T., POBEDIMSKAYA, T. H., NADEZHINA, T. N., and KHOMYAKOV, A. P. (1992) Polymorphism of donnayite (Na,TR)Sr[(C[O.sub.3]).sub.2][multiplied by][H.sub.2]O. Vestnik Moskovskogo Universiteta Seriya 4, Geologiya, No. 5, 69-78 (in Russian).

VARD, E., and WILLIAMS-JONES, A. E. (1993) A fluid inclusion study of vug minerals in dawsonite-altered phonolite sills, Montreal, Quebec: implications for HFSE mobility. Contributions to Mineralogy and Petrology, 113, 410-423.

VLASOV, K. A., ed. (1964) Geochemistry and Mineralogy of Rare Elements and Genetic Types of their Deposits. Vol. II. Mineralogy of Rare Elements (published in Russian). English translation published by: Israel Program for Scientific Translations (1966), 945 p.

VON KNORRING, O., and FRANKE, W. (1987) A preliminary report on the mineralogy and geochemistry of the Aris phonolite, SWA/Namibia. Communications of the Geological Survey of S.W. Africa/Namibia, 3, 61.

VON KNORRING, O., PETERSEN, O. V., KARUP-MOLLER, S., LEONARDSEN, E. S., and CONDLIFFE, E. (1992) Tuperssuatsiaite, from Aris phonolite, Windhoek, Namibia. Neues Jahrbuch fur Mineralogie, Monatshefte, Jg. 1992, 145-152.

WALENTA, K. (1993) Neue Mineralfunde von der Grube Clara. [doyleite] Lapis, 18, No. 1, 17 (in German).

WIGHT, Q., and CHAO, G. Y. (1995) Mont Saint-Hilaire revisited. Rocks and Minerals, 70, 90-103; 131-138.

WOOLEY, A. R. (1987) In: Alkaline Rocks and Carbonatites of the World. Part 1: North and South America. University of Texas Press, Austin. 49-57.

YAKOVENCHUK, V. N., MENSHIKOV, Yu. P., PAKHOMOVSKY, Ya. A., and IVANYUK, G. Yu. (1997) Ancylite-(La), Sr(La,Ce)[(C[O.sub.3]).sub.2][multiplied by](OH)[multiplied by][H.sub.2]O - a new carbonate from a hydrothermal vein, Mount Kukisvumchorr (Khibiny massif), and comparison with ancylite-(Ce). Zapiski Vserossiskogo Mineralogicheskogo Obschestva, 126, 96-108 (in Russian with English abstract).

ZAITSEV, A. N., YAKOVENCHUK, V. N., CHAO, G. Y., GAULT, R. A., SUBBOTIN, V. V., PAKHOMOSKY, Y. A., and BOGDANOVA, A. N. (1996) Kukharenkoite-(Ce) [Ba.sub.2]Ce[(C[O.sub.3]).sub.3]F, a new mineral from Kola Peninsula, Russia and Quebec, Canada. European Journal of Mineralogy, 8, 1327-1336.

ZHANG, P., and TAO, K. (1981) Zhonghuacerite [Ba.sub.2]Ce[(C[O.sub.3]).sub.3] - a new mineral. Scientia Geologica Sinica, 1981, 195-196 (in Chinese with English abstract). Abstracted in American Mineralogist, 67, 1078.

ZHANG, P., and TAO, K. (1985) Cordylite in Bayun-Obo. Scientia Geologica Sinica, (China) 1985, (2), 191-195 (in Chinese with English abstract). Abstracted in Mineralogical Abstracts, 1986 86M/0871.

1 For agpaitic characterization, the agpaitic index or coefficient should be ([Na.sub.2]O + [K.sub.2]O): [Al.sub.2][O.sub.3] = [greater than] 1, and some typical indicator minerals such as eudialyte, rinkite, lorenzenite etc. should be present.
COPYRIGHT 1998 The Mineralogical, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1998 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Horvath, Laszlo; Pfenninger-Horvath, Elsa; Gault, Robert A.; Tarasoff, Peter
Publication:The Mineralogical Record
Date:Mar 1, 1998
Words:25376
Previous Article:Kingsbridge, an early quarrying district on Manhattan Island.
Next Article:Denver Show 1997.
Topics:

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters |