South of
Khao Ploi Waen, near the village of Bang Kha Cha, blue, bluish green and yellow
sapphires are extracted from marine beach placers in silty lowlands in the tidal zone of the Gulf of Thailand.
Dark gray ("black")
star sapphires are of special interest.
Ref: E.Ya. Kievlenko, Geology of gems, 2003, p. 66
Gemstone List