By Robert Weldon and Sally Eaton-Magaña

More than 700 people attended GIA's first-ever Gemological Research Conference (GRC) Aug. 26-27, held just before the 4th International Gemological Symposium. Geared toward a technically inclined audience, it covered several gemological topics, including the geology of gem deposits, new gem localities, gem characterization techniques, gem treatments and laboratory growth of gem materials.

The conference was co-chaired by Dr. James E. Shigley, director of Research for GIA Carlsbad, and Brendan M. Laurs, editor of Gems & Gemology (G&G), and was sponsored by Charles & Colvard, Ltd. A concurrent poster session was organized by Dona Dirlam, director of GIA's Richard T. Liddicoat Gemological Library and Information Center.

Attendees included 121 presenters from around the world, who participated either in oral sessions or through poster presentations; attendance far exceeded initial projections.

"We are delighted with the attendance, but also with the scope of the oral and poster presentations," Laurs said.

"In fact, we're planning on doing it again. Next time, we plan to make the conference longer and introduce different forums, such as panel discussions."

A second GRC is tentatively planned for August 2009.

The goal of the conference was to highlight areas of ongoing gemological research and have a range of oral and poster presentations from individuals in the gem trade, as well as from academia. The industry faces challenges in gem identification and quality grading, which can only be met through practical gemological research, Shigley said.

"We had some great keynote speakers and a good mix of presenters on a wide range of topics," he said. "There is no other event like this in the gemological community, and the conference had some new voices, perspectives and faces."

Attendees were enthusiastic about the sessions. "There was so much sophisticated and important information to learn," said Avi Raz, president of Los Angeles' A & Z Pearls, Inc.

Highlights of Topics

General Gemology
A wide range of topics were covered in the presentations on general gemology. For example, color communications experts and researchers spoke about a variety of color communication systems and devices to aid in conveying the nuances of color in gems.

Menahem Sevdermish, president of Advanced Quality Ltd. in Ramat Gan, Israel, spoke about Gemewizard and possible new applications for this software technology to communicate gem colors.

Donna Beaton, project manager at EGL USA's Gem Identification & Research Department in New York City, took a closer look at how communication is affected by human color perception and how difficult it is to communicate color findings. Beaton proposed a quantitative approach to analyzing gemstone colors, using Padparadscha sapphire with a GemSpec digital imaging spectrophotometer as an example.

George Bosshart, a gemological researcher from Horgen, Switzerland, described a rare reverse color change zircon, which showed a dramatic 180 degree difference in color hue between violetish blue (in daylight) and bluish green (in incandescent light).

Shane McClure, director of West Coast Identification Services at the GIA Laboratory, spoke about a geologic source classification of gem corundum, noting that much of what gem dealers and corundum merchants perceive about a gem's characteristics is determined in part by the geologic environment in which the gem formation took place. McClure concentrated on two main geologic formation types for corundum: metamorphic and magmatic-related. He noted that these types yield repeatable characteristics in corundum, including absorption spectra, growth structures and inclusions. He said this approach could bypass locality-driven information, to instead correlate how a gem's appearance is related to the geologic environment in which it formed.

Geology of Gem Deposits
Geologists from around the world discussed the conditions of the formation of gem deposits, including the formation of granitic pegmatites, the geologic environment in which some important gems form.

Dr. David London, professor of geology at the School of Geology and Geophysics at the University of Oklahoma, spoke about essential structural components in pegmatite gem minerals.

Matthew Taylor, geology Ph.D. student at the Institute of Geological Sciences, Masaryk University of the Czech Republic, related a different model for the formation of gems in pegmatites, suggesting that they grow in supercritical conditions within a dense silicic gel.

Dr. Eloïse Galliou, a professor of gemology at the Institut des Matériaux Jean Rouxel in Nantes, France, discussed the characterization of more than 70 opals from several countries. These were chemically analyzed using ICP-MS to better understand differences between sedimentary and volcanic opal deposits.

Gem Characterization
Speakers discussed various new analytical techniques being used, or about to become available, to characterize the properties of gem materials.

Dr. Emmanuel Fritsch, professor of physics at the Institut des Matériaux Jean Rouxel, stated that although "enabling technology" – sophisticated and often expensive equipment such as LA-ICP-MS and LIBS – is likely to become increasingly important for gem identification, there should be a continued emphasis on "classic gemology" and microscopy to make the majority of gemological distinctions required.

Dr. George Rossman, professor of mineralogy at the California Institute of Technology in Pasadena, echoed many of Fritsch's views, but noted that gem characterization requires observation at the nano-level, which means examining features 1,000 times smaller than those seen with a regular optical microscope.

Nicholas Del Re, manager of Gemological Services, Research and Development at EGL USA, emphasized the importance of imaging spectroscopy as a diagnostic gemological tool. He noted that imaging spectroscopy allows for information about a gem to be captured in the "nth" dimension, and that the technology could be used to detect high pressure/high temperature (HPHT) diamond treatments or natural versus synthetic quartz, among others.

Dr. Bonner Denton, professor of chemistry and geosciences at the University of Arizona in Tucson, gave an assessment of handheld Raman spectrometers that he said could be used outside a laboratory setting.

Dr. Robert Downs, professor of geosciences at the University of Arizona, presented a summary of the RRUFF project, which provides a free searchable database of Raman spectra and other information on minerals. There are 2,000 minerals at various stages of completeness now available in this database.

Dr. Jeffrey Post, curator of the National Gem and Mineral Collection at the Smithsonian Institution, presented a new technique using imaging plate detectors that can provide X-ray diffraction (XRD) pattern of a solid crystal. A sample, such as a gemstone, no longer has to be ground into a powder in order to identify it.

Dr. Christopher Breeding, research scientist at the GIA Laboratory in Carlsbad, presented data obtained from the DTC DiamondView deep-UV imaging system, including the observation that HPHT-treated, type IIb diamond does not show red phosphorescence.

Gem Localities
Several presenters discussed current and new gem deposits at worldwide locations.

Dr. Lawrence Snee, retired from the U.S. Geological Survey and based in Denver, Colorado, spoke about his experiences as a geologist in Afghanistan and of his collaboration with the Afghan Geologic Survey. He said that Afghanistan is interested in reassessing and reopening many of its lucrative gem-bearing sites, including emerald, ruby and lapis lazuli deposits.

Dr. Lore Kiefert, laboratory director at the AGTA Gemological Testing Center in New York City, spoke about an alluvial deposit for sapphires in New Zealand. Following a battery of gemological and chemical analysis tests taken on 30 samples, she says the material found in New Zealand has some characteristics consistent with sapphires from Australia and Cambodia.

Dr. Federico Pezzotta, curator of the Natural History Museum in Milan, Italy, discussed the huge variety of gem materials found in Madagascar, including the recent discoveries of multicolor tourmaline deposits and multicolor sapphire deposits in Fianarantsoa Province.

Bjorn Anckar, a gemologist/geologist based in Lusaka, Zambia with the European Union Mining Sector Diversification Programme, gave an update on the vast amethyst resources found in the Mapatizya mining area in southern Zambia. He detailed the mining and processing operations and also spoke briefly about Zambian ametrine (mixed purple and yellow quartz). He noted that Zambian amethyst is not routinely heated because it transforms into a less marketable gray to green color.

Laboratory Growth of Gem Materials and More General Gemology
This session began with two keynote presentations.

Dr. James Butler, a scientist with the Naval Research Laboratory in Washington, D.C., described recent progress on growing diamond by the chemical vapor deposition (CVD) method for various high-technology applications and potentially for use in jewelry.

Dr. Ichiro Sunagawa, a retired university professor and expert on crystal growth from Tokyo, Japan, described some basic principles of crystal growth in nature and in a laboratory, and how the features of crystals can help to distinguish natural from laboratory crystal growth.

Dr. Sally Eaton-Magaña, technical director of G&G, substantiated Breeding's findings (presented the previous day) by discussing the luminescence spectra of the phosphorescence of synthetic, treated and natural blue diamonds, including the Hope Diamond.

Dr. Laurent Massi, a gemologist at the Institut des Matériaux Jean Rouxel, presented a model that may explain the behavior of the still-puzzling chameleon diamonds. He proposed that the typically observed color of chameleon diamonds (green) is actually the metastable color, compared to the yellow color that appears when the diamonds are heated.

Dr. Yuri Shelementiev, head of the Gemmological Lab at Lomonosov Moscow State University in Moscow, Russia, showed new computer software that can model the appearance of faceted colored diamonds under various lighting conditions and guide cutting decisions of colored rough.

Courtenay Keenan, an instructor at Aurora College in Yellowknife, Northwest Territories, Canada, introduced the college's cutting and polishing school, and the grading system used to train their students.

Stefanos Karampelas, a gemology Ph.D. student at the Department of Mineralogy-Petrology-Economic Geology of Aristotle University of Thessaloniki in Greece and at the Institut des Matériaux Jean Rouxel in Nantes, France, offered research regarding the color of freshwater cultured pearls. Raman spectroscopy shows that several organic pigments are present in the cultured pearls and the color is determined by the combination of these pigments. Surprisingly, these pigments appear not to be part of the carotenoid family.

Richard B. Drucker, president of Gemworld International Inc. in Northbrook, Illinois, and publisher of The Guide, concluded with a summary of pricing trends in recent years for various gemstones including ruby and sapphire.

Diamond and Corundum Treatments
Heat treatments of corundum, as well as a variety of diamond treatments, were topics of great significance to many participants, given their growing prevalence in the gem market.

Dr. Chakkaphan Sutthirat, academic advisor at the Gem and Jewellery Institute of Thailand in Bangkok, spoke of heat treatment experiments on corundum. Among their findings was that heat treatment between one to three hours and at a temperature of around 800-1000 C tended to reduce blue coloration in sapphires, whereas higher temperatures, around 1400 C, resulted in more saturated color.

Kenneth Scarratt, director of research for GIA in Bangkok, Thailand, noted that advancements in the technology of corundum heat treatment require laboratories to also acquire and routinely use sophisticated analytical instrumentation for gem identification. Scarratt said some high-temperature heat treatments, including the diffusion of elements into corundum (such as beryllium), has resulted in sapphire "hybrids" where the distinction between natural and synthetic material is increasingly blurred.

Dr. Mark Newton, a professor in the Department of Physics, University of Warwick in Coventry, United Kingdom, explained the relationship between treated diamonds (using HPHT techniques), and the development of synthetic diamonds using HPHT and CVD growth technologies.

Dr. Jef Van Royen, a scientist at HRD Research in Lier, Belgium, said his group studied several type IaB (rather than the better known HPHT treatments on type IIa) brown diamonds, before and after treatment.

Results were a lessening of the brown body color, resulting in color grades from G-J at lower temperatures (2200 degrees Celsius for 10 minutes), and a creation/intensification of yellowish body color (grades I-O) at higher temperatures.