Luster
Vitreous, Pearly
Vitreous
Pleochroism
-
Weak or absentWalter Schumann
Transparency
-
Transparent, Translucent, Transparent to translucent
Refractive Index
1.653-1.693
1.53-1.55
Crystal System
monoclinic
Triclinic
Birefringence
0.038-0.044
0.007-0.010
Clarity
TransparentUlrich Henn and Claudio C. Milisenda
Transparent to translucent