USA, Southern and central Africa, green, blue, China, India, USA, Italy, green, blue, China, India, USA, Italy
Mexico
H 4Mg 3Si 2O 9Walter Schumann , Gemstones of the world (2001) More from other references
Ca 3B 6O 6(OH) 12 · 2H 2OAnthony et al , Handbook of Mineralogy (2001)