Afghanistan, Australia, Brazil, Kenya, Southern and central Africa, Sri Lanka, Switzerland
Australia, Canada, Guatemala, Italy, Kenya, Mexico, Turkey, Mexico, Guatemala, Mexico, Guatemala
ConchoidalWalter Schumann, Gemstones of the world (2001), ConchoidalWalter Schumann, Gemstones of the world (2001)
Conchoidal, ConchoidalWalter Schumann, Conchoidal