Gem mines, Bo Phloi, Bo Phloi District, Kanchanaburi ...
Gem mines, Bo Phloi, Bo Phloi District, Kanchanaburi Province, Thailand : Mining of alluvial blue sapphire in several open pits. Blue and yellow sapphire, black spinel, and minor zircon have been mined for over three decades (Khamloet et al., 2014).