USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Tanzania, Sri Lanka, China
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Mg 3Al 8BeO 16Walter Schumann , Gemstones of the world (2001) More from other references