Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Al 2O 3Michael OâDonoghue , Gems, Sixth Edition (2006)
Perfect on {001}, very good on {010}, imperfect on {110}
NaAlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)