Thailand is the largest centre of treatment, cutting and trade of sapphire and ruby. In addition to imported raw material, Thai corundum is also processed. Sapphires and rubies have been produced since the end of the 19th century, and were intensely mined in the 1960s.
Ref: E.Ya. Kievlenko (2003) Geology of gems, p. 43
Gemstone List
Gem list contains entries from all listed localities in region.