Luster
-
Vitreous, Pearly
Pleochroism
O = brownish red; E = yellowish red
Dichroic (colorless)
Transparency
OpaqueHerve Nicolas Lazzarelli
Transparent, Translucent
Refractive Index
2.690-3.220
1.530-1.543
Optic Character
-
Uniaxial/-
Crystal System
Trigonal
tetragonal
Birefringence
0.280
0.000-0.003
Clarity
OpaqueHerve Nicolas Lazzarelli
Transparent