Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
1.793.85-3.94
1
7.18
👆🏻
Fracture
Irregular/uneven
Conchoidal, Uneven
Cleavage
Perfect on {10bar10}
{010} Good, {100} Distinct
Mohs Hardness
2.55-5.5
2
10
👆🏻
Chemical Composition
Ca6(Al,Si)2(SO4)2B(OH)4(OH,O)12•26(H2O)
(Mn2+ ,Fe2+ ,Mg,Ca) 2(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth Edition (2006)