Origin
Southern and central Africa
Southern and central Africa
Color
Black, Brownish, Brown
Yellow, Blue, Colorless, White
Specific Gravity
4.5-4.8
3.28-3.31
Fracture
Uneven
Conchoidal
Cleavage
None, parting may develop along {111}
None observed
Mohs Hardness
5.5
6.5-7.5
Chemical Composition
Fe++Cr2O4
Al 6B 5O 15(F,OH) 3Ulrich Henn and Claudio C.
Pleochroism
none.
Colorless
Refractive Index
2.08-2.16
1.638-1.650
Crystal System
Isometric
Hexagonal
Birefringence
-9999
0.0130
Clarity
-
TransparentUlrich Henn and Claudio C. Milisenda
Respiratory
Poor
Excellent
Psychology
Vitality
Clarity
Healing
Emotional healing
Emotional healing
Qualities Associated
Protection
Clarity