Tenacity
Brittle
-
Solubility
Gelatinises in acids
-
Durability
-
-
Specific Gravity
2.4-2.53.85-3.94
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Conchoidal, Uneven
Cleavage
Distinct on {110}
{010} Good, {100} Distinct
Mohs Hardness
5-65-5.5
2
10
👆🏻
Chemical Composition
(Na,Ca)4-8Al6Si6(O,S)24(SO4,Cl)1-2
(Mn2+ ,Fe2+ ,Mg,Ca) 2(PO 4)(F,OH)Michael OâDonoghue , Gems, Sixth Edition (2006)