Conchoidal, Brittle, Conchoidal, UnevenArthur Thomas, Gemstones (2009), Brittle, Conchoidal
Uneven, Uneven, ConchoidalAnthony et al, Handbook of mineralogy (2001), Brittle, Conchoidal
Rare tabular and prismatic crystals. Usually occurs as fibrous, parallel veins that break off into cleavage fragments.
Distinct on {100} and {110}
CaSO 4Michael OâDonoghue , Gems, Sixth edition (2006) More from other references
3NaAlSi 3O 8 · NaClAnthony et al , Handbook of mineralogy (2001)