Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Al 2O 3Ulrich Henn and Claudio C.
Rare tabular and prismatic crystals. Usually occurs as fibrous, parallel veins that break off into cleavage fragments.
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references