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Gem cutter.

You're a What? Gem Cutter For eons, geologic forces worked to form pockets of mineral deposits that dot much of the globe. For millennia, artisans and craft workers cut and polished certain kinds of these minerals, transforming rough, rocklike crystals into stones of beauty and brilliance. And for about a decade, Dave Brackna, following in the footsteps of artisans of old, has crafted countless carats of rubies, emeralds, and other stones--worth nearly $10 million--into gems of the finest quality. As an artist and a craft worker, he is a member of a very select fraternity of perhaps 100 in the world. He is a custom gem cutter.

Gem cutting is actually a second career for Brackna. An encounter with a gemologist, or gem specialist, while shopping for his wife's engagement ring spurred Brackna's initial interest in gems. He found that he could purchase cut stones and then resell them to jewelers. Later, both he and his wife participated in a 6-week gem-cutting class, which provided an introduction to gem-cutting principles and equipment. "There's really no way someone can teach you how to cut gems," he says. "Trial and error is the best way to learn."

Loss of his regular job forced Brackna to learn quickly. "As a hobbyist I often thought that working with gems would be a great way to make a living. Now I had the chance to find out. I was scared, but I gave it a go, and it has worked well. I was lucky, but I also discovered that I have a real talent for it."

A quick inventory of Brackna's handiwork attests to his skill. Dazzling displays of amethysts, garnets, tourmalines, and rubies array his worktable. But, he insists, success came slowly. The first 4 years of cutting were a rough apprenticeship; the next 2, only a bit smoother. "It's been a long road, with a lot of wear and tear, but it's been worth it, both personally and financially. There's nothing better than being your own boss."

Gem Cutting

Gems are cut in either of two fashions: Cabochon or faceted. The surface of a stone may be cut in a convex shape, called a cabochon, or it may be cut with one or more planes, or facets. Translucent stones like opals, that allow little light to penetrate them, are usually rounded. Transparent stones, such as rubies and emeralds, are typically cut in facets.

Brackna works with transparent stones, or "optical minerals" as he calls them. "There is a tremendous range of products in the gem world today," he says. "But try to be a jack of all trades and you'll master none. I am a master faceter."

All gems possess, to one degree or another, three principal qualities that distinguish them from other minerals: Beauty, durability, and rarity.

In a gem, beauty is a composite term, determined by three specific qualities--luster, brilliance, and dispersion, or fire. A casual observer finds it difficult to distinguish between these qualities. To an expert, they are clearly delineated. Proper cutting enhances these effects and the stone's value.

The beauty of a gemstone depends to a considerable degree on its luster, or surface appearance. A gem's luster is somewhat analogous to the texture of a flower, which may be waxy, like a camellia, or have the varnished look of a buttercup. A gem may be waxy, silky, or oily in appearance. Gem specialists recognize eight different types of luster.

The other qualities concern the effect of light upon a stone. Fire or dispersion refers to the prismatic separation of light into spectral colors. For instance, when you turn a diamond in the light and see the distinct flashing of each color of the spectrum, you observe the fire of the stone. Brilliance is the relative amount of light reflected by the stone. Proper cutting enhances these effects.

Besides beauty, durability is necessary to a fine gem. The surface of a gem must be hard enough to resist easy scratching. This ability of a gem to scratch or resist scratches is measured from 10 to 1 according to the Mohs Scale, named after a Viennese mineralogist. It represents the relative hardness of a mineral. The hardest stone is a diamond; it scratches all other stones. Rubies and sapphires rank at 9; an emerald is graded 7.75. The scale descends to 1, which is ascribed to talc, the softest mineral.

Rarity is easy to understand. The scarcer a type of stone is, the more expensive it usually is.

All of these factors play a role in assessing the value of a stone. Brackna asserts that sometimes another category should be considered. Fashion often dictates the price of a stone. From year to year, certain gems become more popular, hence more valuable, than other stones.

Brackna buys most of the stones with which he works in rough crystal form. Others may be "native cut," that is, roughly cut in the country where they were mined. But be they rough or native cut, stones from around the world pass through his fingers--emeralds from Colombia, rubies from Burma and Sri Lanka, garnets from the Ural Mountains in Russia. "I'll cut just about anything but diamonds," he says. "The diamond market is rigidly controlled. I have more than enough work without them."

"A gem cutter is limited only by his imagination," says Brackna, "and by the shape of the rough." A gem cutter will want to use as much of the stone as possible. According to Brackna, yields from a rough stone may vary from 25 to 60 percent of the original weight. (The unit of weight for a gem is a carat, which equals 200 milligrams. Do not confuse this with karat, which is a measure of the purity of gold and equals 1/24 part of pure gold in an alloy.)

"When I buy rough, I'll hold the stone up and look at it under the light from all directions, keeping my finger behind it to reflect the light back into the stones. Every stone has different qualities. I'll visualize the final shape of the stone with these qualities in mind. For instance, the color may be better along one plane. I'll orient the stone to take advantage of this difference." Occasionally he may use heat treatment, in essence baking the stone, or even irradiate the stone. These treatments can alter the stone's color.

In his examination of the gem, he will check for flaws or "inclusions," on the surface or within the crystal itself. He'll cut the stone in such a way as to eliminate the flaw or minimize it.

An essential tool during the examination is a small, simple instrument called a dichroscope. At one end is an eyepiece and at the other a small square opening. Depending upon the internal structure of the stone, a single color or two colors will be visible, helping the gem cutter determine what kind of stone it is. Sometimes these determinations are difficult. "You have to be especially careful these days," says Brackna. "Some synthetic gems can fool even the most practiced eye. If you make a mistake, it can be very, very, costly."

With the preliminaries complete, it's time to begin cutting. "Actually, the term gem cutting is misleading," says Brackna. "What you're really doing is grinding a series of mirrors in a symmetrical manner around a stone." Sometimes the stone may be large enough to yield several smaller gems. In this case, the cutter will use a diamond saw to cut it.

The angle of the facets is important. Properly cut, they reflect light back into the gem. The stone's internal structure affects this. Different stones bend or "refract" light differently. The cutter must be aware of this and adjust the angles of the facets to accommodate the differences.

A faceting machine, similar to an electric sander, is used to grind or cut the facets. Grinding wheels called laps, coated with different grades of abrasives (frequently diamond dust) revolve at high speed. Using wax, the gem cutter glues the stone to a small stainless steel rod called a dopstick, which is then positioned in a mechanical arm at a fixed angle above the lap. With the stone secured, the cutter lowers it to the lap and grinds a facet. The gem cutter proceeds in this fashion, rotating the dop and altering the angle as needed.

A variety of different cuts may be used, such as rose-cuts, which may have from 12 to 24 facets, and brilliant-cuts, which, Brackna asserts, have 57 facets rather than the 58 frequently mentioned in books and advertisements. Brackna has devised his own special designs and has cut some stones with more than 300 facets.

After cutting, the gem will be polished. Special polishing agents are spread on a lap and the stone buffed to a fine gloss. Polishing laps may be made of tin, wood, ceramics, or other materials.

More Work To Be Done

Once the final facet is ground and polished, there is yet more work to be done. "Cutting is a skill," says Brackna. "As a businessman, I have many other tasks I have to attend to." He must market and sell his gems.

During a recent trip to Tucson, where he participates annually in one of the world's foremost gem shows, Brackna realized how important presentation can be. "I noticed how beautiful a friend's stones were and realized that he had mounted them on tiny pedestals rather than arranging them in a display case. I experimented with the same idea, and the small change made a big difference in my sales."

When he first began, Brackna cut on a contract basis for gem dealers or collectors. Now, he principally cuts and sells his own material. "But," he says, "I still do work for those people who supported me during the lean years. They helped me and I won't forget them. Loyalty is important."

There are very few custom gem cutters in the United States. Brackna estimates that there are no more than 25 or 30. Most of the gems mounted and sold in jewelry stores come from cutting centers in Thailand and Germany. "They do an adequate job for their market," he says. "My customers," he says, "are those who know what a quality cut stone is, who can look at it and see that it is unique."

Start Out as a Hobbyist

If you're interested in gem and mineral collecting and cutting, a good way to begin is as a hobbyist. "The first stones I cut and sold came from a big jar of stones that I purchased at a hobby store," says Brackna. "As a matter of fact," he adds, "it's one hobby that can be self-sustaining. There's always a market for good stones, particularly among fellow hobbyists."

"It's tremendously satisfying to take a lump of crystal and turn it into a beautiful gem," he said. "I've cut about 5,000 gems since I began. They're going to be around for a long, long time. In a way, I'm leaving my mark on the world."
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Title Annotation:You're a What?
Publication:Occupational Outlook Quarterly
Article Type:column
Date:Sep 22, 1985
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