Tenacity
-
Brittle
Solubility
-
Dilute acid
Durability
-
-
Specific Gravity
3.26-3.362.93-2.96
1
7.18
👆🏻
Fracture
Conchoidal
Subconchoidal, Conchoidal
Cleavage
Good on {100}
Distinct on {010}, imperfect {110} and {011}
Mohs Hardness
6.5-73.5-4
2
10
👆🏻
Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
CaCO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references