1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
1.5 Fracture
Uneven, Uneven, Conchoidal, Uneven, Gems, Sixth Edition (2006)
Uneven, Brittle, Metallic
1.6 Cleavage
Perfect on {001}, good on {010}
Perfect on [001] imperfect on [100]
1.7 Mohs Hardness
1.8 Chemical Composition
(Na,Ca)Al1-2Si3-2O8
(K,Na) 3(Fe2+ ,Mn) 7Ti 2Si 8O 24(O,OH) 7Anthony et al , Handbook of mineralogy (2001)