Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.20-3.322.90-2.98
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Conchoidal
Cleavage
Poor
Rare tabular and prismatic crystals. Usually occurs as fibrous, parallel veins that break off into cleavage fragments.
Mohs Hardness
6-6.53.5
2
10
👆🏻
Chemical Composition
(Mg,Fe2+ ) 7(SiO 4) 3(F,OH) 2Anthony et al , Handbook of mineralogy (2001)
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references