Often they are dipyramidal without any prism faces. The faces are usually striated perpendicularly. Also there are botryoidal, massive and fibrous forms. Hardness is 3 - 3.5. Cleavage is distinct in one direction, but not usually seen due to twinning.
Fracture is uneven.
Streak is white. Associated Minerals include fluorite , celestite , galena , barite , calcite and aragonite . Best Field Indicators are twinned habits, reaction to acid, fluorescence and phosphorescent under short-wave UV light and density.