1 Optical Properties
1.1 Luster
1.2 Pleochroism
Moderate; cochineal-red to blood-red
Weak: colorless-(greenish) yellow
1.3 Dispersion
1.4 Transparency
OpaqueUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) Rarely transparentMore from other references
Gemmological Tables (2004) More from other references
1.5 Refractive Index
2.792-3.0871.650-1.677
1
3.25
1.6 Optic Character
Not Available
Not Available
1.7 Crystal System
Trigonal
Monoclinic Prismatic H-M Symbol (2/m) Space Group: P 21/a
1.8 Birefringence
0.295-0.2960.019-0.025
0
0.296
1.9 Clarity
OpaqueUlrich Henn and Claudio C. Milisenda
TransparentUlrich Henn and Claudio C. Milisenda