Southern and central Africa
Afghanistan, Pakistan, Burma, Brazil, Madagascar, USA, Canada, Russia, Madagascar, Brazil, Canada, Mexico, Madagascar, Brazil, Canada, Mexico
Uneven, Conchoidal, Uneven, Conchoidal, Gemstones of the world (2001)
Gemstones of the world (2001), UnevenWalter Schumann, Gemstones of the world (2001)