Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Conchoidal, ConchoidalWalter Schumann
Perfect in three directions
CuSiO 2(OH) 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
NaAl 3(PO 4) 2(OH) 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references