Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Perfect on {001}, very good on {010}, imperfect on {110}
NaAlSi 3O 8Michael OâDonoghue , Gems, Sixth Edition (2006)
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