Sapphire often contains minor inclusion of tiny slender rutile needles, which when present decrease the transparency of the stones and are known as silk. Sapphires displaying asterism are known as “Star Sapphires” and these are highly prized.
Sapphire is found in only a few locations around the world. The three most famous regions of Blue Sapphire are Kashmir, Sri Lanka and Burma. The finest Kashmir and Burmese sapphire displays superb color and clarity without any thermal heat treatment.