Luster
Vitreous
Vitreous
Pleochroism
Weak: pink pale pinkHerve Nicolas Lazzarelli
Weak or absentWalter Schumann
Dispersion
0.010.01
0.005
1
👆🏻
Transparency
Transparent, Translucent, Transparent to translucent
Transparent, Translucent, Transparent to translucent
Refractive Index
1.544-1.5531.53-1.55
1
3.25
👆🏻
Optic Character
-
-
Crystal System
Hexagonal
Triclinic
Birefringence
0.0090.007-0.010
0
0.296
👆🏻
Clarity
TranslucentHerve Nicolas Lazzarelli
Transparent to translucent