1 Optical Properties
1.1 Luster
Vitreous
Vitreous, Adamantine, Vitreous, Adamantine
1.2 Pleochroism
Weak: colorless-(greenish) yellow
Strong
1.3 Dispersion
1.4 Transparency
Gemmological Tables (2004) More from other references
Transparent, Translucent, Transparent to opaque
1.5 Refractive Index
1.650-1.6771.762-1.788
1
3.25
1.6 Optic Character
Not Available
Not Available
1.7 Crystal System
Monoclinic Prismatic H-M Symbol (2/m) Space Group: P 21/a
Trigonal
1.8 Birefringence
0.019-0.0250.008-0.009
0
0.296
1.9 Clarity
TransparentUlrich Henn and Claudio C. Milisenda
Transparent