Smaller retailers on the lookout for something unique to give them an edge over the cookie-cutter gemstones featured by mass-market competition might well examine the artistry of some of America’s foremost cutters and carvers. American gem cutting combines rough-hewn knowledge with self-made mastery. As a group, American cutters are not terribly organized, particularly in contrast to Old World cutting centers such as Idar-Oberstein, where cutting secrets have been passed down from parent to child for generations. As a result, American cutters have rarely paid rigid attention to the actual formalities of cutting.

Before John Sinkankas’ classic book Gem Cutting, first published in 1955, little written information existed about the art of cutting gemstones. Consequently, cutters on this continent set out to develop skills on their own. These maverick artists spread in myriad directions and evolved rather like a democracy: a diverse group of individuals with a tapestry of different backgrounds, tastes, opinions and influences. In this haphazard way, North America has become a formidable presence in the cutting world, strengthened by the vision and influences of many individuals. In this first edition of a new JCK series on North American gemstone artists, we examine the common ties that bind these cutters together and the different expressions that make them diverse.

A recently formed organization known as the Gem Artists of North America represents the beginning of a cohesive organization. But American cutting as a body of work is still in its infancy. In many cases, American cutters have no formal education in gemology, cutting and carving or in the tools needed to do the job. Consequently, American cutting has never really been set up for larger production. Instead, it has evolved as a magnet for unique or rare gems, one-of-a-kind collector’s carvings or stones for custom jewelers. A brief look at the following cutters demonstrates how the art has developed in North America.

Beginning with Pebbles

“I’ve been interested in stones forever,” says Arthur Anderson of Speira Gems, Ashland, Ore. The one-time house-painter got his start in 1983 while he was living in Eureka, Cal. “I knew nobody in the gem business, except for an old rockhound who taught me how to cut some basic shapes using beach pebbles,” he explains.

Anderson soon graduated from beach pebbles by acquiring cutting equipment, reading books and learning on the job. “One day I looked at gems in a jewelry store and realized that my standards were much more exacting,” he recounts. Anderson knew then he had become a good cutter. He began to experiment with holographic and internal cutting techniques – a hallmark of his style.

A construction accident in 1991 left Anderson in a wheelchair for about a year, so he focused on gem sculpting and three-dimensional intarsia techniques. “I work hard for that intrinsic aesthetic,” he says. “I can show a stone or a sculpture to a 10-year-old or an 80-year-old, and they both flip out!” Anderson’s “down time” may have been a blessing in disguise. His gems and sculptures are works of art that have won him prizes in the American Gem Trade Association’s Cutting Edge and Spectrum competitions and accolades around the world. His cutting techniques were even detailed in the Gemological Institute of America’s quarterly Gems & Gemology (Winter 1991).

Like Father, Like Son

For Mike Gray of Graystone Enterprises, Missoula, Mont., the path to gem cutting was less circuitous because his father, Buzz, was a geologist and gem cutter. In a way, father and son learned their craft together. “It all started for me in 1968 when my father acquired a benitoite mine,” says Mike, referring to the world’s only source of the rare gem. They had the rough cut overseas, “but the results were horrendous,” he says. “So my father got a faceting machine and we learned together. We used some books and eventually my dad got good enough to be noticed by Ed Swoboda, a gem expert who worked for Pala International of Fallbrook, Cal. Eventually, we ended up there.”

Mike says his father warned him not to become a geologist, a rule he summarily ignored. Between college geology classes, Mike cut gems to earn money. “I was cutting so many different materials that it felt like an apprenticeship,” he says. “We were at the right place at the right time. In the ’60s and ’70s, the Germans were the top and were resting on their laurels. The Sri Lankans were faceting low-quality pebbles, and the Thais were just coming on-line. We thought ‘Why not apply diamond-cutting standards to colored stones?’ From that point on, we cut everything for its optimum beauty rather than weight.”

Mike ponders the downside of his business. “I tend to work a lot harder for myself – I get calls from around the world at all times of night,” he says. “And it’s hard to take vacations. But it’s more exciting than corporate America.” Mike has been published in Gems & Gemology (Spring 1988) and received several awards, including the Best of Species prize at the Tucson Gem & Mineral Show in 1994.


Tanzanite simulants are not all created equally, it seems, though more are created every day.

A tanzanite simulant called “cortanite” emerged last year and was subsequently renamed “chortanite.” The material has virtually the same optical, chemical and physical characteristics as synthetic corundum. Marketed by Gemstones International, Sayreville, N.J., chortanite has a bluish color akin to tanzanite’s. (Tanzanite – a natural gem – is often heat-treated to exhibit saturated purple/blue colors, is a variety of the mineral zoisite and is mined in Tanzania.)

Now another simulant has cropped up. Bob Silverman, president of Lannyte Co., Houston, Tex., says his company markets two tanzanite simulants, though both are known as “coranite™”. “A blue version of simulated tanzanite is synthetic corundum, while a more purple version is a close relative of YAG [yttrium aluminum garnet],” he says. This material is also a compelling visual look-alike and exhibits a pronounced purple. The Gemological Institute of America calls the material “one of the most superficially convincing imitations of gem-quality tanzanite that we have ever seen.” It further described the material as containing “yttrium, aluminum and europium.”

The following table shows a comparison of the characteristics of each of the stones mentioned:


Refractive Index Specific Gravity Hardness
Tanzanite 1.691-1.700 3.35 6-7
Synthetic corundum 1.762-1.770 4.00 9
YAG 1.833 4.60 8.5+

To separate the two simulants, determine optic character and birefringence. YAG is singly refractive and tends to have more dispersion than tanzanite or synthetic corundum. Tanzanite can be separated easily from the two simulants by determining specific gravity or by close microscopic evaluation to detect natural or synthetic inclusions. Silverman says one of the easiest tests to separate the YAG simulant from tanzanite is by looking at the stones under UV fluorescence. “The YAG glows yellow to red, while the natural tanzanite remains blue,” he says. “By passing a UV lamp over a lot of stones, you can tell instantaneously if any of the material is YAG.”


Montana sapphires – to be or not to be? Amid lingering doubts about the viability of producing U.S. sapphires in a consistent, repeatable, efficient way, American Gem Corp., Helena, Mont., continues to grow according to plan. The company has signed agreements to include these gems in the product lines of two major jewelry manufacturers: Michael Anthony Jewelers, Mount Vernon, N.Y., and Landstrom’s, Rapid City, S.D. (see JCK, July 1996, p. 32D).

It’s easy to understand the doubts. Montana sapphires have had a checkered production history, with costs of production consistently edging out profits. But their beauty and desirability have kept the pursuit going.

Now, about a century after the first sapphires were found there by gold prospectors, change is in the air. Since early 1994, when American Gem went public, the company has been building anticipation in the trade for its product. And this might well be the year for Montana sapphires, says Greg Dahl, chairman and chief executive officer.

American Gem has succeeded in conquering three main objectives: to control the majority of potential sapphire-bearing ground in North America, to become one of the world’s largest sapphire producers and to be a fully integrated company that mines, processes and sells sapphires to manufacturers and retailers worldwide.

The first goal was met in the company’s first year as it took control of over 35,000 acres. This past summer, says Dahl, the company worked around the clock to move 1,000 cubic yards of ore per day and obtain 1 million carats of rough per month. Dahl says further modifications in the size of sorting trommels should increase that figure to over 1.5 million carats per month.

In September, the company announced plans to acquire Great Northern, an Australian company that produces 20 million to 25 million carats of sapphires per year. The deal is “subject to due diligence,” but Dahl is “cautiously optimistic.” These Australian sapphires are known for being overly dark. But American Gem’s technical subsidiary – Crystal Research – has developed technology to make the stones lighter.

American Gem’s cutting facility in Sri Lanka facets the gems to exacting standards. It produces about 14,000 calibrated gems per day, says Dahl, and stockpiles are growing. The company plans to have 250,000 cut carats available at the Tucson Gem and Mineral Show this month.

For now, everyone is eager to know how consumers will receive the new sapphire jewelry collections. In addition to the agreements with Michael Anthony Jewelers and Landstrom’s, American Gem plans to test-market the Montana sapphires through major jewelry retailers such as Sterling Inc., J.C. Penney, Zale Corp. and Nordstrom.

American Gem Corp. is bringing the world an unprecedented quantity and variety of calibrated sizes and colors of Montana sapphires. Gems courtesy of American Gem Corp. Photo by Robert Weldon.


The Diamond Dealers Club West Coast will schedule a Market Day this spring based on the success of its first such event in October, says Joseph Bronner, a board member and chairman of the event.

In addition to doing brisk business at the October event, says Bronner, participants had a chance to hear Hidetaka Kato, president of the Tokyo Diamond Exchange, speak about the importance of a strong alliance between Pacific Rim countries and the DDC West.


Diamonds for the connoisseur. That’s how Richard von Sternberg, president of Eight Star Diamond near San Jose, Cal., describes his gems.

The company has made its mark by recutting polished diamonds into “the most precise cut on this planet.” All Eight Star diamonds are round, polished to Tolkowsky proportions (Ideal Cut) but with only a 2% tolerance. Tables range from 54% to 56%, compared with 53% to 57% for traditional Ideal Cuts, for example. In addition, every facet is perfectly joined and aligned with the corresponding facet on the other side, says von Sternberg.

“It takes much longer to polish an Eight Star diamond because of the precision required,” he says. They’re cut by hand because each one has unique grain patterns that machine polishers can’t accommodate properly, he says.

The Eight Star Diamond concept was created in Japan about a decade ago along with the Fire Scope, which measures reflected light from a diamond. If the scope shows the diamond as all red with a perfectly aligned black star pattern, it passes the Eight Star inspection.

Eight Star, (707) 575-4419, fax (707) 575-5841.


Redaurum of Canada has commissioned a new stock offering to raise $3.3 million to expand its diamond mine at Kelsey Lake, Colo., and to explore other U.S. sites.

The company sent a “rights issue” to shareholders in January allowing them to buy additional shares of common stock at $0.25 in Canadian currency. Shareholders received one “right” for each share held. Four rights entitled the shareholder to buy one share at that price.

An investor group agreed to underwrite up to 5.66 million shares if shareholders don’t fully exercise their rights.

Kelsey Lake, the first commercial diamond mine in the U.S., began production this past summer.

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