Luster is vitreous to silky. Crystals are translucent to slightly transparent. Crystal Habits include stubby prismatic or blocky to tabular crystals, sometimes as pseudo-octahedrons. Also acicular, fibrous and capillary and found as encrusting, stalactitic and concretionary masses. Cleavage is perfect in one direct but only distinct in another.
Fracture is conchoidal.
Streak is white. The taste has a sweet, astringent and metallic character. Associated Minerals are epsomite , chalcanthite , gypsum , pyrite , pyrrhotite , marcasite and chalcopyrite . Best Field Indicators are crystal habit, low density, associations, solubility in water, taste and color.