Luster is vitreous or pearly to dull. Crystals are translucent to opaque. Crystal Habits include tabular square crystals dominated by two pinacoid faces. Also as crusts, micaceous, foliated and earthy. Many crystals are pseudomorphs of autunite .
Cleavage is perfect in one direction.
Fracture is uneven. Streak is a pale yellow. Best Field Indicators are color, crystal habit, higher density than autunite , fluorescence, radioactivity, associations and cleavage.