USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Brazil, Tanzania, Zimbabwe, Madagascar, Burma, Sri Lanka, India
Uneven, Uneven, Gemstones of the world (2001) More from other references
ConchoidalGemdat.org, Management Team (2012), ConchoidalGemdat.org, Management Team (2012)
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
(Fe,Mg) 3Al 2(SiO 4) 3gemdat.org , Management Team (2012)