Luster is vitreous to pearly on the main pinacoid. Transparency crystals can be transparent but more commonly are translucent to opaque. Crystal Habits include tabular square crystals dominated by two pinacoid faces. Crystals can look cubic, but the pearly luster only on the pinacoid faces gives the true symmetry away. Also as crusts, micaceous, foliated and scaly aggregates.
Cleavage is perfect in one direction.
Fracture is uneven. Streak is a pale green. Associated Minerals are autunite , uranophane , uranocircite , meta-torbernite , uraninite and other uranium minerals. Best Field Indicators are color, crystal habit, non-fluorescence, radioactivity, associations and brittle cleavage sheets.