Tenacity
Brittle
Brittle
Solubility
-
-
Durability
-
-
Specific Gravity
3.20-3.322.72-2.75
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Uneven
Cleavage
Poor
Perfect on [001], good on [010], imperfect on [110]
Mohs Hardness
6-6.56-6.5
2
10
👆🏻
Chemical Composition
(Mg,Fe2+ ) 7(SiO 4) 3(F,OH) 2Anthony et al , Handbook of mineralogy (2001)
Ca(70-90%)Na(30-10%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)