De Beers / Monopros Reports Modeled Revenues and Grades for Mountain Province Mining's Hearne Diamond Pipe; Value Per Carat has Increased Significantly.

Business Editors

ONTARIO, Canada--(BUSINESS WIRE)--Jan. 31, 2000

Mountain Province Mining Inc., (NASDAQ: MPVIF; TSE: MPV), a diamond exploration and development company, announced today that it has received from its contractor, Monopros Limited (Monopros), a wholly-owned subsidiary of De Beers Consolidated Mines Limited (NASDAQ: DBRSY), the modeled revenue and grade estimates for the Hearne diamond pipe. The modeled value per carat has increased significantly to US $65 per carat from the initial estimate of US $44 per carat based on the 1998 mini-bulk sample while the modeled value per tonne has also increased to US $111 from US $103. The Hearne kimberlite pipe is one of five diamondiferous bodies in the cluster at Kennady Lake, located on the company's AK claims in the Northwest Territories of Canada.

&uot;The Company is very pleased with the significant increase in the value per carat and the increase in the revenue per tonne which is consistent with the number of good quality larger diamonds recovered in the bulk sample.&uot; said Jan W. Vandersande, president of Mountain Province Mining.

The bulk sample of the 5034, Hearne, Tuzo and Tesla pipes was started January 11, 1999 and was completed April 6, 1999. The kimberlite was initially processed at Monopros' dense media separation (DMS) plant at Grand Prairie, Alberta, and the resulting concentrates were shipped to Johannesburg, South Africa, where final diamond recovery was completed. For the Hearne pipe, 856 carats were recovered from 469 tonnes of kimberlite. De Beers valued the recovered diamonds per sieve class in Kimberley, South Africa. The De Beers Mineral Resources Estimation Department has used these current grade and diamond values, together with the mini-bulk sample results and the micro- and macro-diamond results announced previously, to model a global grade (carats per tonne) and a global revenue per carat for each of the parts that make up the Hearne pipe. It is important to note that production recovery factors, determined by De Beers, have been applied and that the commonly used commercial bottom cut-off recovery size of a screen with a 1.50 mm square mesh has been used to determine the grades.

The Hearne pipe consists of two parts, a northern and a southern lobe. The two lobes have been subdivided on the basis of internal geology into several phases. Based on the 1999 bulk sampling results, all parts of the Hearne body except the south lobe Phase E between 200 and 300 meters (called Phase E1) are classified in the Indicated Resource category. Phase E1 remains in the Inferred Resource category. The modeled results for each of these parts of the pipe are summarized in the following table:

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Hearne Pipe           Resource   Modeled grade  Modeled       Revenue
                      (million     (carats      Revenue      Per Tonne
                       tonnes)     per tonne) (US $/carat)    (US $)
----------------------------------------------------------------------
North Lobe Phase A      3.08         2.05          65           133
----------------------------------------------------------------------
North Lobe Phase B      1.61         0.60          65            39
----------------------------------------------------------------------
North Lobe Phase C      0.72         2.05          65           133
----------------------------------------------------------------------
South Lobe Phase D&    1.14         2.05          65           133
----------------------------------------------------------------------
South Lobe Phase E1     0.31         2.05          65           133
----------------------------------------------------------------------
Weighted Average of     6.86         1.71          65           111
       All Phases
----------------------------------------------------------------------

These results compare to a range of modeled values per carat of $25-$50 with a best fit value of $44, a modeled grade of 2.33 carats per tonne, with a resultant revenue per tonne of $103 determined from the 1998 mini-bulk sample for the Hearne pipe. The increase in value per carat is 48 percent and the increase in revenue per tonne is 8 percent. The higher grade phases of the Hearne body (all phases except The North Lobe Phase B) represent 77 percent of the current resource size and have an estimated revenue per tonne of US $133. The modeled grades are based on a three-dimensional model of the pipe taking into account the different phases of kimberlite, (e.g. low and high grade zones). These modeled values are thus the best current global estimates of the grade, value per carat, and expected revenue per tonne for the pipe. The resource size estimate for the Hearne kimberlite body is 6.86 million tonnes to a depth of 300 meters.

Systematic auditing of the processed concentrates (tailings) from the Hearne kimberlite has recovered a few additional diamonds, which have been incorporated into the modeling of the Hearne grades. Auditing of the Tuzo tailings is nearly complete and any additional diamonds recovered will be incorporated into the grade modeling. The modeled grades and values for the Tuzo pipe are expected in late February.

De Beers will combine these revenue values and grades with those from the 5034 pipe (reported December 14th) and the Tuzo and Tesla pipes, when available, to develop a conceptual mine model. A decision to proceed with a feasibility study will be made by De Beers once all the aspects of the model have been studied and considered.

The drilling of four delineation holes was completed in December. One hole was drilled from the SW towards the NE through the 5034-South kimberlite body (located approximately 150 meters SW of the western lobe of the 5034 body). The hole intersected 97 meters (69 meters horizontally projected) of kimberlite. This compares to 31 meters horizontally projected of kimberlite intersected last spring in a drill hole in the SE to NW direction. The next hole was drilled from the east lobe of the 5034 kimberlite towards the east. The hole intersected 44 meters (31 meters horizontally projected) of kimberlite. This extension of the east lobe of the 5034 pipe could add as much as half a million tonnes to the previously reported resource size estimate of 12 million tonnes to a depth of 300 meters for the 5034 kimberlite body. Two holes were drilled into the Faraday kimberlite body, located 12 km NE of Kennady Lake. The first hole intersected successive narrow intersections of kimberlite (varying from 0.4 to 2.1 meters) at a distance of approximately 200 meters NE of the original intersection into the Faraday kimberlite body, reported in April 1999. The second hole intersected 21 meters of kimberlite (15 meters horizontally projected) at a distance of approximately 40 meters NE of the original kimberlite intersection. A decision on how to proceed with work on the Faraday and 5034-South kimberlite bodies will be made after a full evaluation of the results, interpretation of the geophysics and analysis of the indicator mineral results.

Exploration drilling on other parts of the AK claims will start once all the till sample results from the 1999 summer sampling program have been received and analyzed.

The AK and CJ claims, located in the Northwest Territories of Canada, are held 90% by Mountain Province Mining Inc., and 10% by Camphor Ventures (VSE:CFV). As reported in the press release on March 7, 1997, Mountain Province Mining Inc. and its partners have entered into a joint venture agreement with Monopros, under which Monopros has the right to earn up to a 60% interest in the AK and CJ properties.

This release may contain forward-looking statements, within the meaning of the &uot;safe-harbor&uot; provision of the Private Securities Litigation Reform Act of 1995, regarding the Company's business or financial condition. Actual results could differ materially from those described in this news release as a result of numerous factors, some of which are outside of the control of the company.

USA Office: 3633 E. Inland Empire Blvd., Suite 265, Ontario, CA 91764

PH: [phone] CANADA Office: 789 West Pender Street, Suite 1205, Vancouver, B.C. V6C 1H2 PH: [phone] Web Site: www.mountainprovince.com E-mail: [e-mail]