USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Canada, Madagascar, Southern and central Africa, Sri Lanka, USA
Uneven, Uneven, Gemstones of the world (2001) More from other references
Uneven, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001)
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Mg 2Al 4Si 5O 18Ulrich Henn and Claudio C.