The interest about the SAP sapphire mine in Kanchanaburi is that it was a large scale sapphire mining operation believed to be for years the world largest sapphire mine. The SAP investors were former tin mining entrepreneurs from Kanchanaburi region. Due to the low prices for tin at the end of the 1980's and the new sapphire finding near Bo Phloi in Kanchanaburi in 1978, they decided to move from tin mining to sapphire mining as they could use for sapphire the same equipment they were using for tin.