Guatemala, Russia, Columbia, Canada, Italy
Afghanistan, Pakistan, Burma, Brazil, Madagascar, USA, Canada, Russia, Madagascar, Brazil, Canada, Mexico, Madagascar, Brazil, Canada, Mexico
White, Red, Brown, Green, gray
Colorless, pink
Splintery, UnevenArthur Thomas, Difficult, Fibrous
Gemstones of the world (2001), UnevenWalter Schumann, Gemstones of the world (2001)