Optical Properties
Luster
Vitreous
Vitreous, Silky
Pleochroism
Not Available
AbsentWalter Schumann
Dispersion
Not Available
Not Available
Transparency
Translucent, Opaque, Translucent to opaque
Translucent
Refractive Index
1.530-1.543
1.655-1.909
Optic Character
Not Available
Biaxial/+
Crystal System
Trigonal
monoclinic
Birefringence
Not Available
0.108-0.254
Clarity
OpaqueHerve Nicolas Lazzarelli
Translucent
