Tenacity
-
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.355-3.4333.83-3.89
1
7.18
👆🏻
Fracture
Uneven
Uneven, Conchoidal
Cleavage
{???} Good, {???} Good
Perfect on {01 1 1}
Mohs Hardness
-99993.5-4.5
2
10
👆🏻
Chemical Composition
(Ca,Mn2+ ,Fe2+ ) 3Al 2BSi 4O 15(OH)Anthony et al , Handbook of mineralogy (2001)
Fe2+ CO 3Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references