Southern and central Africa
Russia, Brazil, Tanzania, Madagascar, Zambia, Sri Lanka, Burma, India, Color: color change, from bluish green (daylight) to purple, red or brown (incandescent light), Hardness: 8, Refractive index: 1.74 1.77, Density: 3.68 3.80, Chemical composition: BeAl2O4, Crystal structure: orthorhombic, Origins: Russia, Brazil, Tanzania, Madagascar, Zambia, Sri Lanka, Burma
Yellow, Blue, Black, Green, gray
Green
UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009)
Not Available
Ca 2(Mg,Al) 6(Si,Al,B) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
BeAl 2 O 4
Gemmological Tables (2004) More from other references
Transparent, Transparent to nearly opaque