Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Uneven, Subconchoidal, Conchoidal
Zn 2(AsO 4)(OH)Michael OâDonoghue , Gems, Sixth edition (2006)
From the Greek for oblique and fracture, descriptive of the cleavage
(Na,K)AlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)