1 Optical Properties
1.1 Luster
1.2 Pleochroism
AbsentWalter Schumann
Not Available
1.4 Dispersion
3.13 Transparency
Opaque
TransparentUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
3.15 Refractive Index
3.17 Optic Character
Not Available
Not Available
3.18 Crystal System
Trigonal
Monoclinic Prismatic H-M Symbol (2/m) Space Group: B2/b (pseudo-HEX)
3.20 Birefringence
Not Available0.039
0
0.296
5.4 Clarity
OpaqueHerve Nicolas Lazzarelli
TransparentUlrich Henn and Claudio C. Milisenda