Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
Uneven, Subconchoidal, Conchoidal
NaAlSi 2O 6 · H 2OMichael OâDonoghue , Gems, Sixth edition (2006) More from other references
slightly water soluble and in hot hydrochloric acid
Subconchoidal, Uneven, ConchoidalWalter Schumann
Octahedral, perfect on {111}, parting on {011}