Madagascar
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
ConchoidalAnthony et al, Handbook of mineralogy (2001), ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Not Available
(Cs,K,Rb)Al 4Be 4(B,Be) 12O 28Anthony et al , Handbook of mineralogy (2001)
BeAl 2 O 4