Tenacity
Brittle
-
Solubility
-
-
Durability
-
-
Specific Gravity
2.65-2.693.85-3.94
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Conchoidal, Uneven
Cleavage
Perfect on {001}, good on {010}
{010} Good, {100} Distinct
Mohs Hardness
6-6.55-5.5
2
10
👆🏻
Chemical Composition
(Na,Ca)Al1-2Si3-2O8
(Mn2+ ,Fe2+ ,Mg,Ca) 2(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth Edition (2006)