Tenacity
Brittle
Brittle
Solubility
Soluble
-
Durability
-
-
Specific Gravity
3.10-3.203.87-4.14
1
7.18
👆🏻
Fracture
Uneven, Conchoidal
Subconchoidal, Conchoidal
Cleavage
Poor to good on (001)
Poor on {120}, in traces on {001}
Mohs Hardness
6-6.55.5-6
2
10
👆🏻
Chemical Composition
(Mg,Fe) 5(SiO 4) 2(F,OH) 2Ulrich Henn and Claudio C.
TiO 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references