Spring 2000 Gems & Gemology
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SPRING 2000 VOLUME 36 NO. 1 TABLE OF CONTENTS EDITORIAL 1 Breakthrough Technology William E. Boyajian FEATURE ARTICLES 2 Burmese Jade: The Inscrutable Gem Richard W. Hughes, Olivier Galibert, George Bosshart, Fred Ward, Thet Oo, Mark Smith, Tay Thye Sun, and George E. Harlow pg. 4 28 Lapis Lazuli from the Coquimbo Region, Chile Robert R. Coenraads and Claudio Canut de Bon NOTES AND NEW TECHNIQUES 42 Spectroscopic Evidence of GE POL HPHT-Treated Natural Type IIa Diamonds David Fisher and Raymond A. Spits 50 Purple to Purplish Red Chromium-Bearing Taaffeites Karl Schmetzer, Lore Kiefert, and Heinz-Jürgen Bernhardt REGULAR FEATURES 60 Gem Trade Lab Notes 66 Gem News pg. 35 79 The Dr. Edward J. Gübelin Most Valuable Article Award pg. 43 81 Gems & Gemology Challenge 83 Book Reviews 85 Gemological Abstracts 93 Guidelines for Authors ABOUT THE COVER: Jadeite has long been the most prized gem in the Far East, par- ticularly China. The primary source of top-grade material lies in the remote jungles of pg. 51 Burma (now Myanmar). The lead article in this issue, written by the first foreign gemologists allowed access to Myanmar’s jadeite mines in over 30 years, reports on current activity at these mines and the evaluation of rough and fashioned jadeite. These pieces, set with diamonds, illustrate the special quality of Myanmar jadeite. The carving is approximately 4.9 cm high, the butterfly is 8.5 cm wide from wing tip to wing tip; the earrings are 17 mm in diameter, and the oval cabochon is about 15 mm × 11 mm. Courtesy of Ho’s Jewelry, San Gabriel, California. Photo © Harold & Erica Van Pelt––Photographers, Los Angeles, California. Color separations for Gems & Gemology are by Pacific Color, Carlsbad, California. Printing is by Fry Communications, Inc., Mechanicsburg, Pennsylvania. © 2000 Gemological Institute of America All rights reserved. ISSN 0016-626X BreakthroughBreakthrough TechnologyTechnology n March 1, 1999, General Electric Company many sleepless nights, too. But we publicly stated (GE) and Lazare Kaplan International (LKI) then—as we have always believed—that the level of Orocked the jewelry industry when the newly technology used to create new synthetics and treat- formed LKI subsidiary Pegasus Overseas Limited ments would eventually also yield evidence for (POL) announced that it would market diamonds their identification. De Beers has produced quantifi- processed by GE to improve their color, brilliance, able results that, only one year after the introduc- and brightness. The impact of such a claim was par- tion of GE POL diamonds, represent an important ticularly disturbing to firms holding millions of dol- step toward establishing detection criteria. lars of diamond inventory. Even more troubling was the assertion that GE’s process was permanent, irre- This is not, however, the end of the story. It is a versible, and unidentifiable. For years we at GIA had solid beginning to a global effort to solve a poten- heard rumors of such a “whitening” process—and tially devastating problem. GIA has had close coop- had even investigated such claims. But we had not eration with De Beers on this issue for many yet seen definitive proof of such a treatment. months, looking at both gemological and spectral features. De Beers is also working with other Soon after the POL announcement, GIA began a research laboratories in a collaborative effort to series of meetings and discussions with GE and LKI develop the instrumentation needed to produce officials, which yielded a temporary, but somewhat these high-sensitivity spectra for routine use in dia- settling result: LKI would inscribe all such diamonds mond identification and grading. They are testing with “GE POL” on their girdles and submit them to more stones, both HPHT-treated and natural color, GIA for Diamond Grading Reports. The Comments to determine if the criteria will hold for all type IIa section of each report would include the following: diamonds processed in this fashion. “’GE POL’ is present on the girdle. Pegasus Overseas Limited (POL) states that this diamond has been pro- This is also the beginning of a new paradigm in cessed to improve its appearance by General Electric gemology. Of course, there will continue to be Company (GE).” When removal of the inscriptions more and “better” synthetics and treatments. But on some stones was detected last summer, GE and we are confident that, with the right resources, LKI sought a safer, more disclosure-friendly way to detection methodology will keep pace with these bring their diamonds to market, later determining to sophisticated materials and processes. sell the goods directly to select retailers, rather than on the open market in Antwerp. We applaud De Beers for their achievement and, especially, for their support of all research labora- But why am I rehashing something that our astute tories and of the diamond and jewelry trade at Gems & Gemology readers already know? This large. As research continues and further break- issue contains a rather technical article on dia- throughs are made in refining identification crite- mond spectroscopy that may, at first glance, go ria and developing instrumentation, these efforts unnoticed. Yet it is of the highest importance: De will undoubtedly play an important role in ensur- Beers researchers have identified a combination of ing the integrity of the diamond industry to both spectral features that is rarely seen in untreated the trade and the consuming public. type IIa diamonds—and that may prove character- istic of HPHT-treated type IIa’s. De Beers’s breakthrough, part of their massive Gem Defensive Program, appears at this early stage to be pivotal. Last year, many people were in a state of panic over the possibility that the new GE process William E. Boyajian, President could not be detected. Truth be told, we at GIA had Gemological Institute of America Editorial GEMS & GEMOLOGY Spring 2000 1 BURMESE JADE: THE INSCRUTABLE GEM By Richard W. Hughes, Olivier Galibert, George Bosshart, Fred Ward, Thet Oo, Mark Smith, Tay Thye Sun, and George E. Harlow The jadeite mines of Upper Burma (now Myanmar) occupy a privileged place in the If jade is discarded and pearls destroyed, petty thieves world of gems, as they are the principal source of top-grade material. This article, by the first will disappear, there being no valuables left to steal. foreign gemologists allowed into these impor- — From a dictionary published during the reign of tant mines in over 30 years, discusses the his- Emperor K’ang Hsi (1662–1722 AD) , as quoted by Gump, 1962 tory, location, and geology of the Myanmar jadeite deposits, and especially current mining erhaps no other gemstone has the same aura of mys- activities in the Hpakan region. Also detailed tery as Burmese jadeite. The mines’ remote jungle are the cutting, grading, and trading of location, which has been off-limits to foreigners for jadeite—in both Myanmar and China—as P well as treatments. The intent is to remove decades, is certainly a factor. Because of the monsoon rains, some of the mystery surrounding the Orient’s this area is essentially cut off from the rest of the world for most valued gem. several months of the year, and guerrilla activities have plagued the region since 1949 (Lintner, 1994). But of equal importance is that jade connoisseurship is almost strictly a Chinese phenomenon. People of the Orient have developed jade appreciation to a degree found nowhere else in the world, but this knowledge is largely locked away ABOUT THE AUTHORS in non-Roman-alphabet texts that are inaccessible to most Mr. Hughes ([email protected]) Westerners, adding further to jadeite’s inscrutable reputa- is an author, gemologist, and webmaster at tion. The mines of Burma (now Myanmar∗) are the primary Pala International, Fallbrook, California. Mr. working deposits for the most prized gem in the Far East Galibert (FGA, hons.; ING, AG) is a gemolo- gist and Hong Kong–based dealer in colored (figure 1), a stone exceeded in price only by diamond. stones and pearls. Mr. Bosshart is chief This article will draw back the curtain on this enigmatic gemologist, Research and Development, at gem, revealing the manner in which Burmese jadeite is the Gübelin Gem Lab, Lucerne, Switzerland. Mr. Ward, a gemologist, writer, and photog- mined, traded, graded, cut, treated, and faked. Since the rapher, owns Gem Book Publishing, major gemological features of jade have already been exten- Bethesda, Maryland. Dr. Thet Oo is a gemol- sively covered in the literature (Hobbs, 1982; Fritsch et al., ogist and Yangon-based dealer in colored stones. Mr. Smith is a gemologist and 1992; Wang, 1994), emphasis here will be on these lesser- Bangkok-based dealer in colored stones. known aspects. An understanding of jadeite is not limited to Dr. Tay is president of Elvin Gems and Far the technical or exacting, but it also requires a feeling for the Eastern Gemmological Lab of Singapore. Dr. Harlow is curator of Gems and Minerals cultural, textural, and ephemeral qualities that make the at the American Museum of Natural History, study of jade unlike any other in the world of gemstones. New York City. Jade has a rich history in the Orient, especially China Please see acknowledgments at the end of (Box A). Historically, the term jade was applied to any of a the article. number of ornamental materials that could be carved, but Gems & Gemology, Vol. 36, No. 1, pp. 2–26 most importantly amphibole jade, or nephrite. The rich © 2000 Richard W. Hughes green material subsequently found in Myanmar proved to be composed primarily of a different mineral (a pyroxene) and 2 Burmese Jade GEMS & GEMOLOGY Spring 2000 Figure 1. “Windows” cut into this otherwise undis- tinguished boulder from the Myanmar Jade Tract reveal the presence of a rich green in the jadeite beneath the skin.