1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Uneven, ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Brittle, Metallic
1.6 Cleavage
Poor to good on (001)
Perfect on [001] imperfect on [100]
1.7 Mohs Hardness
1.8 Chemical Composition
(Mg,Fe) 5(SiO 4) 2(F,OH) 2Ulrich Henn and Claudio C.
(K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)