Iolite
Hardness ( Moh )
" 7 - 7.5
Crystal System
OrthorhombicSpecific Gravity
2.59
Refractive Index
1.533 - 1.596
Birefringence
Colour(s)
Colorless, Pale blue, Violet, Yellow, Gray.
Cleavage
Francture Type
Conchoidal
Luster
Streak
White
Transparency
Transparent to translucent
Formula
(Mg,Fe)2Al4Si5O18
Country
Found In Australia,Austria,Brazil,Canada,China,Greenland,India,Myanmar,Norway,Sri Lanka,USA