Luster
Vitreous
Not Available
Pleochroism
NilArthur Thomas
O = brownish red; E = yellowish red
Dispersion
Not Available
Not Available
Transparency
Transparent
OpaqueHerve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references
Refractive Index
1.708-1.722
2.690-3.220
Optic Character
Biaxial/+
Not Available
Crystal System
Orthorhombic
Trigonal
Birefringence
0.031-0.050
0.280
Clarity
Transparent
OpaqueHerve Nicolas Lazzarelli