Information
Specific Gravity: 3.50 - 3.84
Hardness: 8.5
Refractive Index: 1.746 - 1.755 ( - 0.005 / +0.005 )
Birefringence: 0.007 - 0.011
Crystal System: Orthorhombic
Luster: Vitreous
Chemical Composition: BeAl₂O₄
Optical Character: Biaxial (+)
Pleochroism: Strong Green, Orange, And Purple-Red Trichroism
Transparency: Transparent To Translucent
Color: Green, Blue-Green, Yellowish-Green To Brownish-Green, Grey. (Colour Changing : Greenish In Daylight, Purplish Or Reddish In Tungsten Light)
Remark: -