GemNotes

Report from Tucson

Exhibitors at the February Tucson gem shows reported brisk business this year, with items in all categories selling well. Suppliers attributed buyers’ upbeat mood to record-breaking sales over the recent holidays, the continuing boom in the economy, and a growing demand for colored gemstones. According to American Gem Trade Asccociation executive director Douglas Hucker, “Consumer awareness of colored gems has never been greater.”

Attendance at AGTA’s Tucson show was never greater, either. Hucker reported a record 9,323 buyers on hand for the six-day Convention Center show, up from 7,632 in 1999. Figures weren’t available for the 20-odd other shows that make up the annual Tucson extravaganza of exhibitions, which include everything from diamonds to healing crystals, but nearly all the shows appeared to be humming.

One of the highlights of the AGTA show was the presentation of its annual Spectrum Awards for jewelry designs incorporating colored gems. This year’s winners (JCK, February 2000, p. 46), which include the jewelry shown on this issue’s cover, were displayed during the AGTA show, and the winners were honored at an evening gala.

But of course the focus was on what suppliers were showing in their cases. Three colored stones—rubellite tourmaline, spessartite garnet, and tanzanite—stood out, and other gems, including Chinese freshwater pearls, were nearly as noteworthy. Treatments were a hot topic, and, not least among this year’s highlights, gems from Greenland made their American debut. Here are the details.

Gem-dandies. Nigerian rubellites. The new rubellites were unusually eye-clean, nearly devoid of the highly visible inclusions so commonly associated with red tourmaline. The color of the bright red material is reported to be natural.

Spessartite garnet. A new find in Nigeria has increased the supply of fine-color spessartites, the finest of which used to come mainly from the “Little 3” mine in California. The Nigerian material can be a tangerine or burnt-orange color. Prices of the saturated orange colors are likely to rise quickly, so now is the time to buy.

Tanzanite. Three years ago tanzanite was selling for $225 per carat; now it’s around $600 per carat, and prices are expected to continue climbing because of its growing popularity. Some jewelers report that they’re now selling more tanzanite than emerald.

Black Tahitian pearls. Production is increasing and prices are falling rapidly. High-quality peacock pearls were available at half the prices paid in 1996.

Round Chinese freshwater cultured pearls. Among the standouts at this year’s AGTA show were Chinese freshwater cultured pearls, which were available in a broad range of colors, sizes, and shapes. These gems, which unlike Japanese akoya pearls are almost all nacre, garnered rave reviews and were labeled by some enthusiasts as “among the finest pearls on earth.” However, they can be even more heavily processed than akoyas, and some may be coated with bee’s wax, according to some experts, or polished and then waxed. Prices, which vary tremendously, are also a concern. The best deals for buyers may be in sizes less than 9 mm and slightly baroque in shape.

Japanese akoyas also sold well, and there’s considerable interest in more unusual pearl material like American and New Zealand cultured abalone pearls.

Pakistani peridot. It’s a purer green than the yellowish-green peridot mined in China and Arizona and costs jewelers $50 to $60 per carat.

Blue chalcedony. A rare and little-known gem from California and Africa, it’s been gaining a small but loyal following, perhaps because it looks so good with platinum, another rising star in the jewelry universe. The best material has a translucent blue with a secondary purple hue. It sells for only $8 to $16 per carat.

Topaz. Prices have fallen 20% to 30%, and Brazil is producing some beautiful specimens with peachy tones. (For information about green topaz, see p. 46.)

Tsavorite. This may have been the most surprising of all gemstones at Tucson. There were great selections, a result of new finds in Tanzania. Consistently larger stones were seen around the shows—5-, 6-, and 7-caraters—which is unusual for the green grossular garnet. And prices for the more common smaller sizes (up to 2 cts.) were priced reasonably but varied from $100 to $400 per carat. With such a wide range of prices and so little difference in quality, one had to shop the show to find the best price.

Treatment talk. “Treatment” vs. “enhancement.” John Koivula, the Gemological Institute of America’s chief research gemologist, introduced the second Photo Atlas of Inclusions by showing off some new photographs from his book, mainly illustrating treatments. He was quick to offer his own point of view on the use of the words “treatment” and “enhancement.” “Treatment is the process, enhancement is the result of that process,” he said.

Pearl waxing. The luster of many Chinese freshwater pearl strands rivaled that of the finest Japanese akoyas, giving rise to speculation about pearl waxing. Lois Berger, a pearl expert and appraiser for Fuller & Associates in McLean, Va., says she actually saw a few pearls coated with wax. Fred Ward, also a pearl specialist, is convinced that pearls were waxed. But some believe the high luster results from fine polishing. According to veteran gem faceters, what matters most to get a fine polish on calcite and aragonite (the two crystals that make up the nacreous layers of a pearl) is not the polishing compound, but the lap. To obtain a high-luster polish on these two very soft crystals, one uses a wax lap with 8,000-grit diamond. More traditional polishing compounds include walnut shells and crushed bamboo.

Oiled ruby and sapphire. Cap Beesley, president of the American Gemological Laboratories in New York, announced that AGL has been seeing widespread use of “oil-type fillers” to clarity-enhance ruby and sapphire. The announcement was made during a scheduled conference to discuss GemCore and the Gemstones Standards Commission, an organization established to promote the proper dissemination of gemstone information to the public. First to sign on was Cartier, which publicly stated it would have “full and complete disclosure results in sales.” The auction houses followed suit, promoting full disclosure in their fine gems and jewelry catalogs.

Other highlights. Concave facets. They’re not just for special stones cut by designer cutters anymore. Now, at least in a few standard shapes, concave-faceted stones are available to a larger market. Eric Braunwart of Columbia Gem House, Vancouver, Wash., showed trays of well-matched round and oval amethysts and citrines. These gems benefit from concave faceting, which increases color saturation. (A darker stone, like the grape garnet, becomes too dark when faceted in this fashion.) Peridot and seafoam-green tourmaline also lend themselves to concave faceting, and a few examples were on hand.

New tanzanite filter. Dr. William Hanneman brought a new filter to Tucson, this one for determining tanzanite from its new lookalike, synthetic forsterite. Hanneman also handed out his new book, Naming the Garnets, a subject that has plagued gemologists for the past two decades. The problem is, when different species of garnets intermix with each other, what do you name them? Hanneman thinks he has the answers.

Exotica. Making their first appearance in Tucson were stones from Greenland. Among the exotic offerings were “tuttupite” (which has a deep red color), green amazonite, blue and white mottled sodalite, and black nuumite. Another out-of-the ordinary exhibit was carved alabaster from Arizona. Paul Hawkins and Susan Zalkind fashion the mineral into a variety of imaginative sculptures, some incorporating inlays of colored gems.

Book report. The new Jewelry Appraisal Handbook, put together for the American Society of Appraisers by Kirk Root, current chairman of ASA, is a folder packed with easy-reference charts and tables for evaluating diamonds and colored gems.

Yasukazu Suwa, the son of a prominent Japanese gem dealer and jewelry manufacturer, shares his knowledge of gemstone quality in Gemstones: Quality and Value, Volume 1. The text has a brief history of each gem, complete with exceptional photographs of loose and mounted gems; discussions of each gem’s origin; and easy-to-use color grids for determining the value of each stone. This book could become a standard reference guide for all gemstone dealers and appraisers.

Daniel Dennis of Home Shopping Network claims to have sold more than 30,000 copies of his book, Gems, A Lively Guide for the Casual Collector. It brings a vast array of gemstone knowledge, including enhancements, to the consumer level but includes a few gemologically misinterpreted comments.

Green Topaz Is Patented

Two years ago in Tucson, gem dealers and retailers saw green topaz for the first time. The sellers of these unusual gems claimed a revolutionary enhancement for the stone—diffusion treatment. Now the treatment is much improved and patented as well.

According to the patent document, Richard Pollak, president of United Radiant Applications Inc. (URA), Del Mar, Calif., is the sole inventor of the process. URA is currently the only company authorized to treat topaz (as well as other gems, including ruby and sapphire) using the methods claimed in the patent. The claims granted in the patent include both the process and the resulting gemstone products, which means if retail jewelers buy treated topaz, they should purchase it from a licensed dealer.

Doug Leslie of Leslie & Co. in San Diego, a licensed distributor of the “evergreen” variety, says the diffusion process has significantly improved since we first reported it a year ago. JCK also examined the newly treated stones, and our judgment is equally positive. The depth and purity of color is impressive.

“Evergreen” is the varietal name that Leslie has attached to its pure medium-dark-green product. The original medium-blue-green color continues to be marketed by M.P. Gem Corp. of Los Angeles. But the recent trend toward the more pure green has spurred M.P. president Ken Moghadam to stock more pure greens. “We purchase about 90% of Pollak’s production,” says Moghadam. Leslie and M.P. have been the major marketers of the enhanced topaz.

Gemologists studying the gemstone’s surfaces used to wonder whether the treatment was merely a coating. In the summer of 1998, the Gemological Institute of America published a study stating that it could be a diffusion treatment, but the color was so thin it was hard to be certain. Now, with the patent in the public domain, the ambiguity has been cleared up.

From the beginning of the treatment, the inexpensive gem material has sold well and has become even more popular as the gemstones have taken on a richer hue. A teal-colored topaz may be coming next. “It was actually a mistake in the treatment process,” said Leslie. After a few weeks of retracing its steps, URA was able to consistently duplicate the color, and it’s currently market testing the new product.

Negotiations have begun to license other parties to produce and market topaz, ruby, and sapphire enhanced by the new process. In the meantime, however, URA says it will vigorously enforce the patent against unlicensed manufacturers, distributors, and sellers.

If you’re selling green topaz, it would be wise to question your supplier to make sure he holds a license from URA.

Learn Gem Carving

Dillman’s Creative Arts Foundation in Lac du Flambeau, Wis., is again sponsoring Ute Klein Bernhardt’s gem carving class, scheduled for June 25-July 1. Bernhardt has been teaching gem carving at Dillman’s since 1989. “I want to help those who are interested in bringing out the inherent beauty of the stone,” she says.

Bernhardt was the first woman to become a master gem carver from the carving school in Idar-Oberstein in her native Germany. Specializing in bas-relief, intaglio-carving design in gem-quality minerals, she’s an inductee in the U.S. National Lapidary Hall of Fame. Some of her more recent important pieces, “Marshall Field I,” carved from an 1,800-ct. flawless green beryl, and “Life Cycle of the Axis Deer,” a 5,000-ct. Madagascar bicolor aquamarine, are in the Field Museum of Natural History in Chicago.

In her classes, Bernhardt uses both gemstone and glass. The basics of carving, such as the knowledge of a gem’s hardness and structure, along with the capabilities of carving tools, will be covered. The emphasis will be on understanding the three-dimensional form that the student will later carve.

Dillman’s is located on White Sand Lake. The phone number is (715) 588-3143.