Australia, Spain, Brazil, Germany, Australia, Spain, Brazil, Germany, Australia, Spain, Brazil
Afghanistan, Pakistan, Burma, Brazil, Madagascar, USA, Canada, Russia, Madagascar, Brazil, Canada, Mexico, Madagascar, Brazil, Canada, Mexico
Conchoidal, Splintery, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle
Gemstones of the world (2001), UnevenWalter Schumann, Gemstones of the world (2001)