Tenacity
Solubility
Durability
Specific Gravity
Fracture
Cleavage
Mohs Hardness
Chemical Composition
(Mg,Fe2+ )Al 2O 4Gemdat.org , Management Team (2012) More from other references
Distinct on {100} and {110}
3NaAlSi 3O 8 · NaClAnthony et al , Handbook of mineralogy (2001)