Southern and central Africa
USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
K(Al,Cr) 3Si 3O 10(OH) 2Gemdat.org , Management Team (2012)
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references