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
Brown, Brown, Green, Green, gray, White
Green
Gedrite Magnesiogedrite , Comments: Dark gray cleavage fragment of magnesiogedrite (gedrite). , Location: Bamble, Telemark, Norway. , Scale: See Image.
1,1 ; 3,2.
(Mg,Fe2+ ) 2[(Mg,Fe2+ ) 3Al 2](Si 6Al 2)O 22(OH) 2Anthony et al , Handbook of mineralogy (2001)
BeAl 2 O 4