Luster
Not Available
Not Available
Pleochroism
O = brownish red; E = yellowish red
Not Available
Dispersion
Not Available
Not Available
Transparency
OpaqueHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
Gemmological Tables (2004) More from other references
Refractive Index
2.690-3.220
1.635-1.663
Optic Character
Not Available
Not Available
Crystal System
Trigonal
Not Available
Birefringence
0.280
0.0170-0.230
Clarity
OpaqueHerve Nicolas Lazzarelli
Gemmological Tables (2004) More from other references