Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.26-3.362.97-3.03
1
7.18
👆🏻
Fracture
Conchoidal
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Good on {100}
{001} Poor
Mohs Hardness
6.5-77
2
10
👆🏻
Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
CaB 2(SiO 4) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references