USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Southern and central Africa, Orange, blue, Orange, blue
Uneven, Uneven, Gemstones of the world (2001) More from other references
Irregular, Irregular, Gemstones of the world (2001)
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
CaCO 3Ulrich Henn and Claudio C.