Colombia, Color: Red, Orangey Red, Orange, Yellow, color shift to Green, Hardness: 6 6.5, Refractive index: 1.55 1.56, Density: 2.66 2.70, Chemical composition: (Na, Ca)(Si, Al)4O8, Crystal structure: triclinic, Origins: Congo, Tibet.
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
Red, Yellow, White, gray, Green, Yellow, Red, Colorless, gray, Yellow, Green, White
Green
Uneven, Uneven, Conchoidal, Uneven, Gems, Sixth Edition (2006)
Not Available
Transparent, Translucent, Transparent to translucent
Transparent, Transparent to nearly opaque