Tenacity
-
-
Solubility
-
-
Durability
-
-
Specific Gravity
3.355-3.4332.70-2.75
1
7.18
👆🏻
Fracture
Uneven
Conchoidal
Cleavage
{???} Good, {???} Good
From the Greek for luster, for its pearly luster on the cleavage.
Mohs Hardness
-99994.5-5
2
10
👆🏻
Chemical Composition
(Ca,Mn2+ ,Fe2+ ) 3Al 2BSi 4O 15(OH)Anthony et al , Handbook of mineralogy (2001)
Al 2(PO 4)(OH) 3Michael OâDonoghue , Gems, Sixth Edition (2006)