Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
From the Greek for oblique and fracture, descriptive of the cleavage
(Na,K)AlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
Uneven, Conchoidal to uneven, ConchoidalWalter Schumann
Distinct on {110}, imperfect on {010}, poor on {001}