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Spring 1999 Gems & Gemology

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Spring 1999 Gems & Gemology SPRING 1999 VOLUME 35 NO. 1 TABLE OF CONTENTS EDITORIALS 1 Symposium ‘99—You Can’t Afford to Miss It! Alice S. Keller 2 The Dr. Edward J. Gübelin Most Valuable Article Award FEATURE ARTICLES pg. 5 4 The Identification of Zachery-Treated Turquoise Emmanuel Fritsch, Shane F. McClure, Mikhail Ostrooumov, Yves Andres, Thomas Moses, John I. Koivula, and Robert C. Kammerling 17 Some Diagnostic Features of Russian Hydrothermal Synthetic Rubies and Sapphires Karl Schmetzer and Adolf Peretti 30 The Separation of Natural from Synthetic Colorless Sapphire pg. 25 Shane Elen and Emmanuel Fritsch REGULAR FEATURES 42 Gem Trade Lab Notes 47 Gem News 61 Gems & Gemology Challenge 63 Book Reviews 65 Gemological Abstracts 77 Guidelines for Authors pg. 31 ABOUT THE COVER: For thousands of years, turquoise has been used in jewelry pg. 57 and other items of adornment. In recent times, much of this material has been treated to improve its appearance and wearability. In particular, a relatively new, proprietary treatment has been used to enhance millions of carats of turquoise for the last decade. Referred to here as the “Zachery treatment,” it cannot be detected by standard gemological techniques. The lead article in this issue describes the properties of this treated turquoise and discusses methods to identify it. All of the turquoise shown here, which is from the Sleeping Beauty mine in Arizona, has been treated by this method. The necklace is composed of 12.5 mm turquoise beads sep- arated by diamond rondelles, with a white gold clasp containing 1.65 ct of dia- monds. The carving measures 30 × 60 mm. Courtesy of Roben Hagobian, Glendale, 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. © 1999 Gemological Institute of America All rights reserved. ISSN 0016-626X Symposium ‘99 You Can’t Afford to Miss It! or months now, GIA has been talking about identification of new treatments, synthetics, and simu- the Third International Gemological lants. Entering the 21st century, suppliers and retailers Symposium. You’ve received a brochure. alike are looking for new marketing opportunities, both You’ve seen ads in this and other publications. via conventional retail channels and through such elec- FYou’ve read the articles and heard about it from your tronic media as television and the Internet; all of these friends. San Diego, June 21-24, 1999, ‘Meeting the will be addressed. New to Symposium this year are the Millennium.’ What is it really, and why am I, as editor of four War Rooms—on appraisals, disclosure, branding, Gems & Gemology,urging you to go? and diamond cut—where attendees and panelists will interact to find solutions to such pressing issues as cut To answer the latter question first: for your own good. grading and the new L.K.I.-G.E. ‘processed’ diamonds. GIA has held only two other international symposia in the last 17 years. Each brought together the most impor- But Symposium offers even more. It offers 70-plus poster tant people in the international gem and jewelry commu- sessions with in-depth introductions to specific new tech- nity both as participants and attendees. Many niques, instruments, localities, and the like. of the topics introduced at the 1991 It offers the insight of four prominent nonin- Symposium set the stage for tackling the dustry experts in the areas of marketing, gemological challenges of the 1990s, technology, the economy, and ethics for such as fracture-filled and synthetic the new millennium. It offers powerful diamonds, jade identification, pearl advice from world business leaders such research, and emerald treatments. as Peter Ueberroth and the senior states- The technological advances of the man of the diamond industry, Maurice past decade have been mind Tempelsman. boggling —and, as a jeweler or gemol- ogist, you are accountable to your cus- And Symposium is not just about learning. tomers to know how to address new syn- Symposium is also about meeting old friends thetics, treatments, and deceptive practices as and making new ones, while enjoying superb food soon as they appear in the market. You also need to and entertainment in one of the world’s most beautiful know the new marketing practices that work in the U.S. settings: the Hyatt Regency, on San Diego Bay. The and worldwide, must be able to anticipate periods of eco- opening reception is at Embarcadero park, right on the nomic instability in the diamond and colored stone mar- water; Tuesday follows with a visit to the ‘Nature of kets, and must be aware of new and declining localities Diamonds’ exhibit at the San Diego Natural History for gem materials. The 1999 Symposium will give you Museum, and a buffet under the stars. On Wednesday, more of the tools you must have to operate successfully in there will be a pearl reception and fashion show. our industry. Symposium closes with Italian cuisine and a unique salute to the history of the Italian jewelry industry, ‘Arte So, exactly what is Symposium? The core of the program in Oro.’ is a series of concurrent speaker and panelist sessions that will address such topics as sources, production, and eco- Please, take my word for it. There is nothing like it. And nomics and manufacturing for both diamonds and col- there will be nothing like it for many years to come. The ored stones. Also included are sessions on pearls, jewelry June 1999 International Gemological Symposium is one design, and estate jewelry, as well as—of course—the event you truly can’t afford to miss. Editorial GEMS & GEMOLOGY Spring 1999 1 The Dr. Edward J. Gübelin Most Valuable Article Award he readers of Gems&Gemology have voted, and your choices for the Dr. Edward J. Gübelin Most Valuable Article Award for best article published in 1998 reflect the increasing importance of advanced research in the T practice of gemology. Receiving first place is “Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Brilliance” (Fall 1998), in which the authors used computer modeling to tackle one of the most com- plex and controversial issues in the trade, the evaluation of diamond cut. Second place goes to “Characterizing Natural- Color Type IIb Blue Diamonds” (Winter 1998), a comprehensive study of blue diamonds and their color classification. The third-place winner, “Separating Natural and Synthetic Rubies on the Basis of Trace-Element Chemistry” (Summer 1998), used semi-quantitative chemical analysis to address a critical gem identification problem. The authors of these three articles will share cash prizes of $1,000, $500, and $300, respectively. Following are pho- tographs and brief biographies of the winning authors. Congratulations also to Ron Lotan of Ramat Gan, Israel, whose ballot was randomly chosen from the many entries to win a five-year subscription to Gems& Gemology. First Place Modeling the Appearance of the Round Brilliant Cut Diamond: An Analysis of Brilliance T. Scott Hemphill, Ilene M. Reinitz, Mary L. Johnson, and James E. Shigley Scott Hemphill, a GIA research associate, has been programming com- puters for the past 30 years. Mr. Hemphill received a B.Sc. in engineer- Scott Hemphill Ilene M. Reinitz ing and an M.Sc. in computer science from the California Institute of Technology. Ilene Reinitz is manager of Research and Develop-ment at the GIA Gem Trade Laboratory (GIA GTL), New York, and an editor of Gem Trade Lab Notes. Dr. Reinitz, who has co-authored many arti- cles for G&G and other publications, received her Ph.D. in geochemistry from Yale University. Mary Johnson is manager of Research and Development at GIA GTL, Carlsbad, and editor of the Gem News sec- tion. A frequent contributor to G&G, she received her Ph.D. in mineral- ogy and crystallography from Harvard University. James Shigley is direc- Mary L. Johnson James E. Shigley tor of GIA Research in Carlsbad. Dr. Shigley, who has been with GIA since 1982, received his Ph.D. in geology from Stanford University. He has written numerous articles on natural, treated, and synthetic gems. 2 Gübelin Most Valuable Article Award GEMS & GEMOLOGY Spring 1999 Second Place Characterizing Natural-Color Type IIb Blue Diamonds John M. King, Thomas M. Moses, James E. Shigley, Christopher M. Welbourn, Simon C. Lawson, and Martin Cooper John King is laboratory projects officer at GIA GTL, New York. Mr. King received his M.F.A. from Hunter College, City University of New York. With 20 years of laboratory experience, he frequently lectures on colored diamonds and laboratory grading procedures. Thomas Moses, vice presi- John M. King Thomas M. Moses dent of Identification Services at GIA GTL, New York, attended Bowling Green University in Ohio before he entered the jewelry trade more than 20 years ago. He is a prolific author and an editor of the Gem Trade Lab Notes section. Please see the first-place entry for biographical information on James Shigley. Christopher Welbourn is head of the Physics and Patents Departments at De Beers DTC Research Centre in Maidenhead, United Kingdom. Dr. Welbourn, who joined the De Beers Research Centre in 1978, holds a Ph.D. in solid state physics from the University of Reading. Simon Lawson is a research scientist in the Physics Department of the De Beers DTC Research Centre. He obtained his Ph.D. in optical C.M. Welbourn Simon C. Lawson spectroscopy of diamond at King’s College London and has published numerous papers on this topic. Martin Cooper, who also joined De Beers more than 20 years ago, is research director at the De Beers DTC Research Centre.
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