Color is white, colorless, reddish, gray or yellowish. Luster is vitreous. Specimens are translucent to opaque. Crystal Habits include granular, earthy and encrusting masses. Individual short prismatic crystals are rare.
Cleavage is perfect.
Fracture is conchoidal. Streak is white. Associated Minerals include trona , blodite , halite , alunite , thernardite , sylvite and other more rare evaporite minerals. Notable Occurrences include Mt. Etna, Sicily and Mt. Vesuvius , Napoli, Campania, Italy as well as Galicia, Poland and Stassfurt, Saxony, Germany. Best Field Indicators are associations, density, habit, fracture and environment of formation.