corundum, Thailand.12, Cambodia.12, gems

Rubies in Thailand and Cambodia are found in the border area of both countries, in the areas of Pailin (Cambodia) and Chanthaburi-Bo Rai-Trat (Thailand). Although being recovered for over 100 years, Thai and Cambodian rubies have been mined intensively in the 1960’s-1990’s. Those were large-scale mechanized operations. Production today has dropped drastically, but small scale and artisanal miners are still finding rubies. These are mainly on the Cambodian side of the border. For this study, 41 samples were analyzed at the GIA laboratory in Bangkok. Internal features were documented with a focus on mineral inclusions, fingerprints and twinning planes. Advanced techniques such as UV-VIS-NIR spectroscopy were used to analyze the color of these rubies. Trace element chemistry was measured using LA-ICP-MS to support the spectroscopy and to compare this data with rubies from other deposits.