Luster
Vitreous
Vitreous
Pleochroism
Weak: colorless-(greenish) yellow
Weak or absentWalter Schumann
Dispersion
0.020.01
0.005
1
👆🏻
Transparency
-
Transparent, Translucent, Transparent to translucent
Refractive Index
1.650-1.6771.53-1.55
1
3.25
👆🏻
Optic Character
-
-
Crystal System
Monoclinic Prismatic H-M Symbol (2/m) Space Group: P 21/a
Triclinic
Birefringence
0.019-0.0250.007-0.010
0
0.296
👆🏻
Clarity
TransparentUlrich Henn and Claudio C. Milisenda
Transparent to translucent