Information
Specific Gravity: 2.66 ( -0.02 / +0.03 )
Hardness: 7.0
Refractive Index: 1.544 - 1.553 ( -0.03 / +0.03 )
Birefringence: 0.009
Crystal System: Trigonal
Luster: Vitreous
Chemical Composition: SiO₂
Optical Character: Uniaxial (+)
Pleochroism: Weak To Moderate Pruple And Reddish-Purple
Transparency: Transparent To Translucent
Color: Purple, Violet.
Remark: -