1 Physical Properties
1.1 Tenacity
1.2 Solubility
Not Available
Not Available
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
3.26-3.363.50-3.60
1
7.18
1.5 Fracture
Conchoidal, ConchoidalArthur Thomas, Gemstones (2009)
Uneven, Brittle, Metallic, Brittle, Metallic, Brittle, Metallic
1.6 Cleavage
Good on {100}
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
1.7 Mohs Hardness
1.8 Chemical Composition
(Ca,Fe,Mn,Mg) 3Al 2BSi 4O 15(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.