USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Canada, USA, Southern and central Africa
Uneven, Uneven, Gemstones of the world (2001) More from other references
Uneven, Uneven, Gemstones of the world (2001) More from other references
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Ca 10Mg 2Al 4(SiO 4) 5(Si 2O 7) 2(OH) 4Ulrich Henn and Claudio C.