Luster is vitreous to pearly on the main pinacoid. Transparency crystals can be transparent to translucent. Crystal Habits include platy square crystals usually in bladed aggregates. Also as crusts, micaceous, foliated and scaly aggregates. Sometimes in attractive rosettes.
Cleavage is perfect in one direction.
Fracture is uneven. Streak is a yellow tint. Associated Minerals are autunite , uranophane , torbernite , meta-torbernite , uraninite and other uranium minerals. Best Field Indicators are color, crystal habit, fluorescence, radioactivity, associations and density.