Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.26-3.363.43-3.44
1
7.18
👆🏻
Fracture
Conchoidal
-
Cleavage
Good on {100}
None Observed
Mohs Hardness
6.5-76.5-7
2
10
👆🏻
Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
Ca 2(Mg,Al) 6(Si,Al,B) 6O 20Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references