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GIA Gemological Research Conference

The Manchester Grand Hyatt in San Diego, where the GIA Symposium and the Gemological Research Conference are being held.

The Gemological Institute of America (GIA) kicked off its fourth gemological symposium with a new event, the Gemological Research Conference. Lasting a day and a half, the conference was packed with 64 presentations on a variety of technical subjects, in addition to 62 "poster sessions," booths with poster presentations of a gemological topic. The conference attracted more than 700 participants, selling out before it started.

One of the main themes was the role of new technology in gemology. Emmanuel Fritsch of the Institut des Matériaux Jean Rouxel in France kicked off the discussion with a forecast of the gemological techniques that he believed would shape gemology in the next decade.

Fritsch focused on three broad categories: First, luminescence, which he says is "where Raman spectroscopy was 25 years ago," in terms of cost, availability, and exploring its use in gemology. Second, trace element analysis, where techniques like Laser Induced Breakdown Spectroscopy (LIBS), Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), and Energy Dispersive X-Ray Fluorescence (EDXRF) are used to make a detailed analysis of the elements in a gem. Third, isotopic studies, which again use advanced technology to map the composition of a gemstone; in this case, they measure the level of certain isotopes. Isotope analysis has already been used on emeralds to determine not only country of origin, but in some cases the mine as well.

Other speakers discussed other uses of those same technologies. Ahmadjan Abduriyim of the Gemmological Association of All Japan (GAAJ) described how they use LA-ICP-MS to determine origin in ruby, sapphire, emerald, and copper-bearing tourmaline. Steve Lowry of Thermo Electron Corporation talked about how several different companies are developing hand-held units that can perform Raman spectroscopy. Jeffrey Post of the Smithsonian Institution demonstrated how X-Ray diffraction could be used to quickly and easily identify rare and unusual gemstones. Nicholas Del Re of EGL USA talked about how imaging spectroscopy can be used to obtain much more complete information about a gemstone by combining spectral information with measurements of spatial relations and intensity.

Robert T. Downs of the University of Arizona is head of the RRUFF Project. He and his students are compiling a database of Raman spectra, X-ray diffraction, and chemical data for every known mineral. The database, which is accessible online (http://rruff.info), currently contains information on approximately 2,000 minerals, with more added on a regular basis. The Raman spectra especially will allow more people to use Raman spectrometers to identify gemstones and minerals by giving them standard spectra to compare their results against.

But at the end of the day, high-tech equipment isn't the be-all of gemology — "classical" gemology is even more important. That was one of the points underlined by Shane McClure, the GIA's director of West Coast identification services, in his proposal of a new method of classifying ruby and sapphire.

Traditionally, ruby and sapphire have been classified as Type I, II, III, or IV, depending on features like the type of inclusions present, growth pattern of the crystals, and so on. But there is another factor which has just as much of an effect on the way a gemstone looks — the geological conditions under which it grew. Gemstones from three widely separated deposits, such as Sri Lanka, Kashmir, and Madagascar, might be visually identical because they all formed in metamorphic rock. To describe a sapphire as "metamorphic Type II," for example, gives a much more accurate picture of what the gem might look like than saying it's from Sri Lanka or Burma.

The theme of identifying ruby and sapphire continued on day two, concentrating on using advanced technology to get more and better information.

Leading the charge was Hiroshi Kitawaki of the GAAJ, who addressed the issue of low-temperature heating of corundum. The primary way that laboratories in the past have identified heat-treated corundum is by looking at mineral inclusions, since most of those inclusions will melt at a lower temperature than its host corundum. Kitawaki showed evidence that ultraviolet and infrared spectra could be used to detect heating to temperatures as low as 600 C. The GAAJ also uses laser tomography, in which a laser beam is used to scan a crystal, and the crystal structure can be mapped from the pattern produced. Heating of corundum, even at low temperatures, produces a dramatic change in the pattern.

However, the next speaker, Chakkaphan Sutthirat of the Gem and Jewelry Institute of Thailand (GIT) challenged these findings, particularly the use of infrared. They performed heating experiments on sapphires in a variety of colors from many sources, taking readings before and after heating. They found that the spectral feature that the GAAJ was using to make its determination of heating disappeared at high temperatures. "I would like to conclude that [infrared] spectra are unclear to determine heated stones," Sutthirat said. "We have to do more experiments."

Other presenters discussed the role of beryllium in coloring gemstones through diffusion. Visut Pisutha-Arnond, also of the GIT, demonstrated that beryllium by itself cannot change the color of a sapphire when diffused into its structure; the beryllium works in conjunction with magnesium and either iron or chromium to create yellow or orange colors.

Pisutha-Arnond's GIT colleague Pornsat Wathanakul reported that a process that starts with heating a sapphire to turn it blue, then beryllium-diffusing it to turn it yellow, and then reheating it in a reducing atmosphere can produce a much better shade of blue than heating alone. She also cautioned that they have found blue sapphires that contain beryllium naturally, which will pose a challenge for gemologists who are trying to determine if the gem has been diffused or not.

Kenneth Scarratt of GIA Thailand discusses the treatments of ruby and sapphire.

But it was Kenneth Scarratt, head of GIA Thailand, who put the cap on the discussion of high-tech treatments: "Most modern labs are having to invest in very expensive pieces of equipment [which can detect] 20 parts per million of beryllium in sapphire, and sometimes much less. As we move forward, we invest more and more and more . . . There are very few labs around the world that can afford the kind of equipment needed to produce the kind of results required by the trade. My prediction for the future is, there will be a small number of gemological labs around the world, and they will have to cooperate among themselves and share information." He compared it to seeing a specialist for a medical problem — if one lab doesn't have the answer, the client may have to go see another lab for a proper identification.

From the Trenches

The other major theme of the Gemological Research Conference was sources — the geology of deposits, models for how gemstones form in the ground, and updates on production.

Frederico Pezzotta of the Natural History Museum in Milan, Italy, discussed recent gem discoveries in Madagascar. The talk centered around a new find of multicolored tourmaline in Fianarantsoa province. There are now 16 deposits being mined in that district, of which only one was known before 2005. In an area known as Camp Robin, seven tons of multicolored tourmaline have been produced since September 2005, mostly liddicoatite and elbaite. Some of those are very large crystals, up to 32 inches long.

Lawrence W. Snee of Global Gems and Geology talked about how the U.S. Geological Survey is helping Afghanis to map their mineral deposits, including gemstones. Snee has already helped to map and collect samples from the emerald mines in Panjsher, ruby deposits in Jegdalek, and lapis mines in Badakhstan. International agencies are helping the Afghanis to get funding to develop their mining industry and profit from these resources.

Robert E. Kane of Fine Gems International reported on a visit to the Hkamti jadeite mining area in northern Myanmar (formerly Burma). One of the major mining areas in that region, Nansibon, produces jadeite in a wide range of colors, from fine "imperial" green to white, lavender, yellow, and black (although further testing showed that the black was not true jadeite). The area has approximately 175 one-acre claims and 500 mines, most of which are mined by individuals using low-tech techniques, but one, the Hja Maw Mine, was being mined by more advanced mechanized methods.

Bjorn Anckar of the European Union Mining Sector Diversification Programme is working in Zambia to help develop their amethyst mines. Production of amethyst in Zambia averaged 1,000 metric tons annually over the last decade. The most active mining area is Mapatizya, with 14 mines, one of which is a large mechanized operation employing 440 people. The rest are smaller operations. The mechanized company, Kariba Minerals, exported 1.2 million kilograms of amethyst in 2005, 70 percent of which went to China and 30 percent to India. He noted that some Zambian amethyst on the surface turns light green when exposed to the heat of brush fires, but the locals are not performing such treatment purposely due to a perceived lack of market for light green quartz.

Richard Drucker of The Guide during his presentation "Social, Political, Economic, and Gemological Impacts on Pricing Trends."

In the geological presentations, heated debate broke out between proponents of two different models for gemstone formation. David London of the University of Oklahoma described "melt" formation, in which rock systems melt under high temperature and pressure, and the mingling of rarer elements with the elements that form the basis for most gemstones — silicon, aluminum, and oxygen — allows gemstones to form in a boundary zone called a pegmatite.

Matthew C. Taylor of Masaryk University in the Czech Republic presented the "gel" model of gemstone formation. In this model, rather than the elements mixing together when different types of rock come into contact in the form of magma, the elements are already present in the form of a "silicic gel," a thick solution of the different elements that releases magmic liquid as it cools and crystalizes, creating pockets of gemstones in the rock.

The presentations given at the Gemological Research Conference tended to be highly technical, and even the trained gemologists among the participants said the subject matter was often over their head. Despite this, participants were positive about the conference overall, and the popularity of these sessions has prompted the GIA to explore having more such conferences in the future.

The end of the Gemological Research Conference was immediately followed by the opening of the International Gemological Symposium 2006, which will conclude on August 29.

July/August 2006 • Dubai: Color in the City of Gold • Reader's Choice Award: Hometown Girl • Gem Imports: U.S., Europe, Japan • In This Issue