Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Perfect on {001}, imperfect on {110}
(K,Na)Ca4Si8O20(F,OH)•8(H2O)
Conchoidal, Splintery, Fibrous
Perfect on {010}, distinct on {100}
CaSO 4 -2(H 2O)Arthur Thomas , Gemstones (2009)