Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Perfect on [001], good on [010], imperfect on [110]
Ca(70-90%)Na(30-10%)(Al,Si)AlSi 2O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
Uneven, Conchoidal to uneven, ConchoidalWalter Schumann
Distinct on {110}, imperfect on {010}, poor on {001}