When you run a gemological laboratory in Bangkok, you never know that might come across your desk.

            While the city is home to the widest selection of natural colored gemstones in the world, it also has a reputation for attracting some of the most ingenious fakes and frauds. And as the mad scientists of Bangkok strive even harder for unnatural improvements of their products, some weird items end up arriving at the Asian Institute of Gemological Sciences (AIGS) for analysis.

            In his lecture at the AGTA show in Tucson, the director of AIGS, Ken Scarratt, informed a standing-room only crowd of the latest trends—as well as the latest tricks—of stone producers in the Bangkok market.

            For example, Scarratt told the story of a client who recently visited AIGS with what was supposed to be a piece of jadeite. After analysis, it was determined that the stone was a piece of quartz, stained green, and impregnated with polymer in order to make it look like a polymer-impregnated piece of jadeite. In the process, this stone had been injected with so much polymer that it could almost be called plastic.

            In another case, a visitor recently arrived at AIGS with a piece of corundum that had apparently been coated with chromium. “It did have a nice metallic sheen, but I couldn’t figure out why they had done it,” said Scarratt.

            A possibility may be that this was a case of a diffusion treatment gone wrong. The stone had been coated with chromic oxide, the coloring agent in ruby. The coating also contains trace elements of lead.

            The moral of these stories? “People will do almost anything to get something that looks like a marketable piece,” said Sacrratt.

            For this reason, the position of AIGS as a watchdog for the local industry is critical. “We need every weapon we can employ to combat these things.” said Scarratt. The laboratory recently invested heavily in new equipment, which has made it arguably one of the finest gem laboratories in the world.

            Later, Scarratt addressed another question on the minds of many gem dealers: is the flow of Mong Hsu ruby slowing down?

            For a first-hand opinion, Scarratt told of a recent trip—his first--to Mae Sai in northern Thailand. Not surprisingly, the first place that he went was the city’s well-known Ruby Lane.

            Scarratt was a little disappointed by what he saw on sale until he went into a courtyard where a friend’s father was doing business. There he saw large amounts of big Mong Hsu rubies on sale, with estimated sizes of five carats and up.

            “This effectively allayed any doubt in my mind that the flow of Mong Hsu was slowing down,” said Scarratt.

            Unfortunately, the flow of Chatham synthetics fashioned to look like Mong Hsu has not slowed down either, according to Scarratt. With AIGS’ Energy Dispersal X-Ray Fluorescence machine, which detects the trace elements in any stone, naturally occurring gemstones and synthetics can be clearly differentiated. Genuine Mong Hsu ruby has detectable elements of titanium, vanadium, chromium and iron, while generally only chromium and small amounts of iron can be found in the Chatham product.

            Other problematic items encountered regularly at the laboratory are polymer impregnated jadeite, synthetic amethysts, and Kashan ruby.

            Synthetic amethysts have become a problem for the industry worldwide because they are virtually indistinguishable from the naturally-occurring stones.

            As for Kashan, it has become a regular fixture on the Bangkok market. After its reintroduction more than a year ago, said Scarratt, “For months, literally almost every day, a Kasshan came into the lab for identification.”

            At first, Scarratt said, the synthetic rubies were easily identified. But after gem producers started heat-treating the stones, identification has become more difficult.

            As for new trends in the local market, Scarratt mentioned Thailand’s increasing appetite for emeralds.

            “People normally don’t associate Bangkok with emeralds,” he said. “But we see large emeralds—50 carats and up –coming through the lab on a fairly regular basis.”

            Other new stones that have been arriving at AIGS are sapphires from the border area of Mozambique and Tanzania. While these are classified as sapphires, their color is actually more of a garnet-like red. Scarratt praised the “very, very nice inclusions” of these stones.

            A surprising visitor to Bangkok is heat treated Montana sapphire. “I don’t know why it’s appearing in Thailand,” said Scarratt, “because it’s going straight back to America afterwards.

            Though Scarratt spent much of his time talking about the problems and perils of the local market, in his summary he tried to point out the bright side of doing business in Bangkok, “When most people visit Bangkok, all they see is the traffic and the pollution,” he said. “I see a very beautiful country, with wonderful people and some of the most fantastic beaches in the world. And the gem market, of course, is the most exciting you’ll find anywhere. So when I talk about the down side, I regard it as the exciting side.”—DAVID SQUIRES