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  TAB LE O FC O N TE N TS  ABOUT THE COVER: Geophysics has the potential to play an increasingly important role in gemstone exploration. Advances in geophysical technology and computer imag- ing now permit mapping of geologic features at various depths beneath the Earth's sur- face. Seismic-reflection profiling and georadar are particularly promising for high-reso- lution mapping of near-surface pegmatites, similar to the one in the Mesa Grande dis-trict of San Diego County—the Queen mine—that yielded these beautiful tourmalinecrystals. Extremely rare, these blue tops measure about 12.5 cm (5 inches) across;the tallest crystal is about 17.5 cm (7 inches) high. Courtesy of Pala International,Fallbrook, California.Photo © Harold & Erica Van Pelt—Photographers, Los Angeles, CA.Color separations for Gems & Gemology are by Effective Graphics, Compton, CA.Printing is by Cadmus Journal Services, Baltimore, MD. © 1997 Gemological Institute of America All rights reserved.ISSN 0016-626X 1EDITORIALThe Dr. Edward J. Gübelin Most Valuable Article Award Alice S. Keller  FEAT   URE ARTICLES4Applications of Geophysics in Gemstone E   x   ploration Frederick A. Cook  2   4Rubies and Fancy-Color Sapphires from Nepal Christopher P. Smith, Edward J. Gübelin, Allen M. Bassett, and Mache N. Manandhar  42Gemological Properties of Near-Colorless Synthetic Diamonds  James E. Shigley, Thomas M. Moses, Ilene Reinitz, Shane Elen, Shane F. McClure, and Emmanuel Fritsch REGULAR FEATURES54Gem Trade Lab Notes6   0Gem News71 Gems  & Gemology  Challenge73Gemological Abstracts  pg. 5  pg. 33  pg. 43  pg. 64   It is with great pleasure that we announce that Dr. Edward J. Gübelin has agreed to have his name associated with Gems & Gemology'  s most valuable article competition. One of the industry's most respected scientists, Dr.Gübelin's name has been synonymous with gemology for over 60 years. He has written numerous books and arti-cles (including the paper on Nepal rubies in the present issue), published a comprehensive map on world gem local-ities, and even produced films on the historic Burmese ruby and jadeite deposits. Photoatlas of Inclusions inGemstones, co-authored with John I. Koivula, is perhaps his best-known contribution; the more than 1,400 pho-tomicrographs are unparalleled in both their quality and the information they convey. In Dr. Gübelin's honor, theaward has been renamed the Dr. Edward J. Gubelin Most Valuable Article Award.Beginning this year, as a result of Dr. Gübelin's generosity, the first-place winner of the Dr. Edward J. GübelinMost Valuable Article Award will receive a plaque, and winners of the second- and third-place awards will be givencertificates. Awards of $1,000, $500, and $300, respectively, will also be given to the authors of the three articlesthat our readers selected as the most valuable papers published in 1996.Receiving the Gübelin plaque for the 1996 first prize is the article De Beers Natural versus Synthetic DiamondVerification Instruments, by De Beers researchers Christopher M. Welbourn, Martin Cooper, and Paul M. Spear.This Fall issue article describes the research behind, and the operation of, two ground-breaking new instruments toseparate natural from synthetic diamonds. Another article about diamonds, although from a completely differentperspective, won second place: A. J. A. Bram Janse's A History of Diamond Sources in Africa: Part II. (Part I ofMr. Janse's article won third place in last year's contest.) John I. Koivula, Robert C. Kammerling, Dino DeGhionno,Ilene Reinitz, Emmanuel Fritsch, and Mary L. Johnson co-authored this year's third-place winner, GemologicalInvestigation of a New Type of Russian Hydrothermal Synthetic Emerald. Both the second- and third-place arti-cles appeared in the Spring 1996 issue.Photographs and brief biographies of the winning authors appear below. Congratulations also to MargaretAlexander of Mimbres, New Mexico, whose ballot was randomly chosen from all submitted to win the five-yearsubscription to Gems & Gemology. F I R S T P L A C E CHRISTOPHER M.WELBOURN M   ARTIN COOPER PAUL M. SPE   AR Christopher M. Welbournisprincipal scientist in the PhysicsDepartment at De Beers DTCResearch Centre, Maidenhead,United Kingdom. Dr. Welbourn,who joined the De BeersResearch Centre in 1978, has aPh.D. in solid state physics fromthe University of Reading. He has published several papers on the use of optical spectroscopy and X-ray andcathodoluminescence topography to study diamonds. Research director at De Beers DTC Research Centre, MartinCooperhas a B.Sc. in physics from the University of London and a M.Sc. in materials science from BristolUniversity. Paul M. Spearis a research scientist in the Physics Department at De Beers DTC Research Centre.With De Beers since 1986, he has a Ph.D. from King's College, University of London. T HE D R. E DWARD J.G ÜBELIN M OST V ALUABLE A RTICLE A WARD A LICE S.K  ELLER, E DITOR  Christopher M.Martin CooperPaul M. Spear Welbourn Gubelin AwardG EMS & G EMOLOGY Spring 19971  S E C O N D P L A C E A. J. A. BR   A   M JA   NSEA. J. A. Bram Janseis manager of his own geological consulting company—ArchonExploration Pty Ltd, in Perth, Western Australia—and a director of KWG Resources,Montreal, Canada. During the 38 years he has been involved with diamond explo-ration, he has worked on projects in Australia, Brazil, Canada, India, and SouthAfrica. He has a B.Sc. in geology and a M.Sc. in petrology and mineralogy from theUniversity of Leiden in the Netherlands, and a Ph.D. in petrology from theUniversity of Leeds in England. He is currently developing an extensive database ondiamond and kimberlite occurrences. T H I R D P L A C E JOH   N I. KOI   V   ULA ROBERT C. KAMMERL   ING DINO DEG   HIONNO IL   ENE REIN   ITZ E   M   M   AN   UEL FRI   TSCH M   ARY L. JOH   NSON John I. Koivula,chief researchgemologist at the GIA Gem TradeLaboratory (GIA GTL), is co-editor ofthe Gem News section of Gems & Gemology. World renowned for hisknowledge of inclusions, Mr. Koivulaholds bachelor's degrees in chemistryand mineralogy from EasternWashington State University. The lateRobert C. Kammerlingwas vice-presi-dent of research and development at GIA GTL, then in Santa Monica, California. Aprolific author, he was also an associate editor of Gems & Gemology  and co-editor ofthe Gem Trade Lab Notes and Gem News sections. Dino DeGhionnois senior staffgemologist at GIA GTL, Carlsbad, California, and a contributing editor to the GemNews section of Gems & Gemology. Before he joined GTL, Mr. De Ghionno workedfor 14 years as a teacher and later manager of GIA's resident student program in colored stone identification.Ilene Reinitzis a research scientist at GIA GTL in New York. A regular contributor to the Gem Trade LabNotes section and a co-author of several Gems & Gemology  articles, she has a Ph.D. from Yale University.Emmanuel Fritschis a professor of physics at the Gemology Laboratory, Physics Department, University ofNantes, France. He has a Ph.D. from the Sorbonne in Paris. His research specialties are spectroscopy in gemolo-gy, the srcin of color in gem materials, and treated andsynthetic gems. Mar   y L. Johnson,also a co-editor of Gems & Gemology  's Gem News section, is a researchscientist at GIA GTL. Dr. Johnson, has co-authored sev-eral articles in Gems & Gemology  , is a Gem Trade LabNotes contributing editor, and is a frequent contributorto the journal's abstract section. She holds a Ph.D. inmineralogy and crystallography from HarvardUniversity. From left, John I. Koivula, Dino De Ghionno, and Mary L. JohnsonA. J. A. (Bram) Janse Ilene Reinitz Robert C. Kammerling Emmanuel Fritsch 2 Gubelin AwardG EMS & G EMOLOGY Spring 1997
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