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Fall 2006 Gems & Gemology 2006 Gia gemological research conference The identification and characterization of natural, synthetic, and treated gem mate- rials remain essential to ensure continued confidence among consumers. Today, gemological research to address these issues is expanding in many exciting directions that encompass a range of scientific fields. To bring together researchers from these diverse disciplines, as well as a wide variety of participants from academia and the gem and jewelry industry, GIA hosted the Gemological Research Conference (GRC) in San Diego on August 26–27, 2006. This conference provided an open forum for scientists and other specialists from around the world to discuss cutting- edge developments in gemology. The program consisted of 60 oral presentations (including 12 invited speakers) and 61 posters, covering the six conference themes. Each abstract was reviewed by selected GRC committee members and edited for clarity. All 121 of these abstracts, plus 28 abstracts from the Symposium Poster Session, are reproduced on the following pages. More than 700 people registered for the GRC, and two sold-out field trips to the Pala gem-pegmatite district were held before and after the conference. GIA thanks Charles & Colvard Ltd. for their generous financial support of this inaugural event. In addition, several donors supplied funds for GRC travel grants (see inside front cover of this issue). The Pala mine owners, as well as Pala International/The Collector in Fallbrook, are thanked for making their properties available and providing excel- lent service during the field trips. Our goal is to hold the Gemological Research Conference on a regular basis. The next GRC is scheduled for the San Diego area in August 2009. We look forward to seeing—and working with—all of you there. James E. Shigley and Brendan M. Laurs Co-Chairs, 2006 Gemological Research Conference 81 photomontage abstracts of grc Oral presentations 84 Diamond and Corundum Treatments 87 Gem Characterization Techniques 93 General Gemology 106 Geology of Gem Deposits 111 Laboratory Growth of Gem Materials 112 New Gem Localities 119 Poster Session Abstracts 79 Organizing Committee The following research scientists and gem dealers are thanked for their help in review- ing abstracts, chairing sessions, and providing advice in shaping the content and form of the 2006 GIA Gemological Research Conference. Diamond and Corundum Treatments Alan T. Collins King’s College, London Filip De Weerdt HRD Research, Lier, Belgium Kenneth Scarratt GIA Thailand, Bangkok Gem Characterization Techniques Emmanuel Fritsch Institut des Matériaux, Nantes, France Frank Hawthorne University of Manitoba, Winnipeg, Canada Franck Notari GIA GemTechLab, Geneva, Switzerland George R. Rossman California Institute of Technology, Pasadena, California Karl Schmetzer Petershausen, Germany General Gemology Shigeru Akamatsu K. Mikimoto & Company, Tokyo Jaroslav Hyrs`´l Kolin, Czech Republic Lore Kiefert AGTA Gemological Testing Center, New York John M. King GIA Laboratory, New York Shane F. McClure GIA Laboratory, Carlsbad Russell Shor GIA, Carlsbad Christopher P. Smith GIA Laboratory, New York Ichiro Sunagawa Tokyo, Japan Wuyi Wang GIA Laboratory, New York Geology of Gem Deposits Lee A. Groat University of British Columbia, Vancouver, Canada George E. Harlow American Museum of Natural History, New York A. J. A. (Bram) Janse Archon Exploration, Carine, Australia David London University of Oklahoma, Norman, Oklahoma William (Skip) Simmons University of New Orleans, Louisiana J. C. (Hanco) Zwaan National Museum of Natural History, Leiden, The Netherlands Laboratory Growth of Gem Materials Vladimir Balitsky Institute of Experimental Mineralogy, Chernogolovka, Russia James E. Butler Naval Research Laboratory, Washington, DC New Gem Localities Edward Boehm JOEB Enterprises, Solana Beach, California Anthony R. Kampf Natural History Museum of Los Angeles County, California Robert E. Kane Fine Gems International, Helena, Montana 80 GEMOLOGICAL RESEARCH CONFERENCE San Diego, August 26–27 People • Places • Events Top left and top right: GRC co-chairs James Shigley and Brendan Laurs. Middle: Oral pre- senter Richard Drucker analyzes pricing trends. Above: Christoph Krahenmann, Mona Lee Nesseth, and Betty Sue King. Near right: Walter Leite and Cristina Baltar with Sergio Costa. Far right: Pornsawat Wathanakul reports on beryllium- treated blue sapphires. Near right: Poster pre- senter A.J.A. (Bram) Janse and Poster Session chair Dona Dirlam. Far right: Makhmout Douman’s poster presen- tation. 2006 GEMOLOGICAL RESEARCH CONFERENCE GEMS & GEMOLOGY FALL 2006 81 Top, left to right: Speakers Ahmadjan Abduriyim, Jim Clanin, and Nikolai Sobolev. Above: Saturday lunch. Middle: Lore Kiefert poses a question. Near right: top, attendees visit some of the 93 posters; below, Michael Wise presents his poster on hiddenite deposits. Above: Dino DeGhionno GRC presenters and Emmanuel Fritsch. Elisabeth Strack (far Directly above: the Saturday left) and Menahem evening cocktail reception. Sevdermish (second from right) enjoy a break with their colleagues. 82 2006 GEMOLOGICAL RESEARCH CONFERENCE GEMS & GEMOLOGY FALL 2006 Two field trips to the Pala pegmatite district rounded out the GRC. Top left: Elizabeth R mine owner Roland Reed shows specimens to field trip participants. Top right: Israel Eliezri inspects a screening apparatus. Middle, left: Roland and Nata Schluessel stand next to a kunzite-bearing pock- et. Below: Pala Chief mine owner Bob Dawson with field trip participants. Above: Kunzite specimens from the Elizabeth R mine. Right: Stewart mine owner Blue Sheppard guides a group of participants. 2006 GEMOLOGICAL RESEARCH CONFERENCE GEMS & GEMOLOGY FALL 2006 83 oral presentation abstracts Diamond and Corundum Treatments and caused identification challenges in gemological laboratories. Recently, Ramaura synthetic rubies have been heated, and this Identification of Heat-Treated Corundum created new problems in identification. When fused orange flux Hiroshi Kitawaki ([email protected]), Ahmadjan Abduriyim, and Makoto Okano is observed under magnification, it can provide an indication of Gemmological Association of All Japan (GAAJ), Tokyo a heated Ramaura synthetic ruby. However, minute inclusions, In accordance with September 2004 revisions to regulations color distribution, and growth zoning should be carefully ob- concerning disclosure on gem identification reports, 27 labora- served, as they appear quite similar to those of natural ruby. tories belonging to the Association of Gemmological Laboratories Japan (AGL) began issuing descriptions of heat Treated Diamond: A Physicist’s Perspective treatment in corundum. However, some reports from different Mark E. Newton ([email protected]) gem laboratories were not consistent with the treated status of Department of Physics, University of Warwick, Coventry, United Kingdom certain stones (especially between Japanese and overseas labora- The technologies for the synthesis of diamond via high pres- tories). Here we introduce the methods used in our laboratory sure, high temperature (HPHT) and chemical vapor deposition for identifying heated and unheated corundum. In addition, we (CVD) techniques are becoming more refined. The progress is studied the identification characteristics of various kinds of created by scientists and technologists wishing to exploit the heated synthetic corundum. remarkable properties of diamond in a wide variety of applica- Detailed observation of internal features is very important to tions, as well as producing gem-quality synthetic diamonds. identify heat-treated corundum. Most crystal inclusions have a Synthetic diamond can be treated, post synthesis, to modify the lower melting point than the host corundum, and may melt or as-grown properties and to improve performance in some high- become discolored by heat treatment. Liquid inclusions are often tech devices. Also, treatments can change the color of natural “healed” by heating, and some substances such as flux can be and synthetic gem diamond. observed in fractures as residues. Additionally, absorption spectra In parallel with the developments in diamond synthesis and in the UV-Vis and IR regions may show changes after heating. treatments, the understanding of the defects (both intrinsic and Non-basalt-related blue sapphires heated in a reducing impurity related) that influence the color of natural and syn- atmosphere show absorptions related to O-H bending that are thetic diamond continues to improve. The physics of diamond not seen in unheated samples. Similarly, heated Mong-Hsu defect interactions has been extensively studied over the last 30 rubies show absorptions related to O-H bending because of the years, and observing the defects that are created or destroyed dehydration of diaspore inclusions. Laser tomography is through HPHT annealing, irradiation, and combinations of extremely useful in the identification of heated and unheated both has contributed to our present understanding of diamond. corundum, and can clearly detect scattering images of crystal From this body of knowledge, we have developed the discrimi- defects such as dislocations, as well as variations in fluorescence. nation techniques that can be used in gem laboratories to iden- Synthetic ruby can also be heated, and the resulting alter- tify treated diamonds. ation of internal features can make these stones more difficult to In nature, annealing typically occurs at modest tempera- identify. In the early 1990s,
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