1 Physical Properties
1.1 Tenacity
1.2 Solubility
1.3 Durability
Not Available
Not Available
1.4 Specific Gravity
3.30-3.403.50-3.60
1
7.18
1.5 Fracture
Conchoidal, Brittle, Conchoidal
Uneven, Brittle, Metallic, Brittle, Metallic, Brittle, Metallic
1.6 Cleavage
{010} perfect, {110} distinct, {100} in traces
Good on {110}, (110) ^ (1 1 0) ≈87°; parting on {100}
1.7 Mohs Hardness
1.8 Chemical Composition
AlO(OH)Walter Schumann , Gemstones of the world (2001) More from other references
(Na,Fe,Ca)Si 2O 6Ulrich Henn and Claudio C.