Physical Properties
Tenacity
Brittle
Brittle
Solubility
Not Available
Not Available
Durability
Not Available
Not Available
Specific Gravity
2.65-2.69
3.97-4.05
Fracture
Uneven, Uneven, Conchoidal, Uneven, Gems, Sixth Edition (2006)
Conchoidal
Cleavage
Perfect on {001}, good on {010}
No true cleavage
Mohs Hardness
6-6.5
9
Chemical Composition
(Na,Ca)Al1-2Si3-2O8
Al 2 O 3
