Afghanistan, Australia, Brazil, Kenya, Southern and central Africa, Sri Lanka, Switzerland
Afghanistan, Brazil, Southern and central Africa, Madagascar, Russia, USA, Zimbabwe
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)