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