By Larne Boyles

George Rossman, Ph.D., professor of Mineralogy at the California Institute of Technology, wondered early in his career how natural lavender jade got its color. Often, by the time specimens made it into his laboratory, they had been either heat treated or dyed. So when he had the opportunity to travel to the major source of the material in Myanmar (a Southeast Asian country formerly known as Burma) in 2002, he was eager to go.

Rossman shared the details of his trip with a slide show presentation titled, “Myanmar: A Journey to the Source of the Jade,” with GIA students and staff Aug. 18. The presentation was the third in the “Gems and Jewelry Brought to Light” lecture series, hosted by the GIA Museum. From Buddhist shrines adorned with gold to gem markets bustling with activity, he enthralled audience members with a peek into a part of the world few Westerners have seen.

Myanmar, the largest source of jade in the world, has an estimated 55 kilometer (34 mile) jade vein running beneath the Ubu River in the northern part of the country. Even with current mining activity, Rossman estimates less than .01 percent of the volume of the jade pocket has been mined.

The audience was surprised when he showed a slide of the entrance to Jade Mine No. 109. The walls of the 70-foot long, 20-foot high and 16-foot wide cavern were formed from solid natural lavender and imperial jade. The mine was turned into a national monument soon after it was excavated because it is the world’s largest block of jade – and the vast majority of it is gem quality, he said.

Rossman also shared images of local fabrication “factories,” one-to-two man operations in makeshift wood booths in Mandalay’s commercial jade market. There, workers used old foot-petal machines to quickly spin stalks of bamboo that polished jade cabochons.

“Bamboo is a silica accumulating plant so it is abrasive,” he said. “That’s why we can’t recycle it in our green recycling bins in Pasadena (California).”

Rossman’s journey also led him to colored stone mines. At the Nam Ya Ruby Mine, he showed how gemstones are hydraulically mined from limestone and clay and sifted through a vibrating table into a canister. Miners sort through the canister once a month to select the best stones, then the clay and other gravel materials are washed down a hillside.

The major gem market in Myanmar is under government control, however local residents are welcome to find, buy and sell small gems to tourists. Rossman had the opportunity to purchase gem material from one of the locals, but his translator discouraged him from paying too high a price for the goods.
 
“As a scientist, I need to know the exact locality of the stones we research,” he said. “It’s often hard to come by enough rough material from the same locality, so I was determined to bring back one of these bags of gems.”

The translator finally approved a bag just as the group was about to leave the mine. The audience “oohed” as Rossman showed a slide of the gem material within the bag – corundum, zircon and a pile of 3-6 mm red spinels.

The real treasure of the trip, he said, were specimens of recently mined lavender jade given to him as a gift from the military commander in charge of Jade Mine  No. 3.

“Here were these beautiful, lavender specimens that had not been exposed to any sort of treatment process,” he said. “I brought them back and finally concluded that the color in this material was caused by the presence of manganese in its +3 oxidation state. I finally had the answer to a question that had been bothering me for years.”