Color varies from the typical emerald green to yellow. Luster is vitreous, pearly on cleavage surfaces. Crystals can be transparent to translucent. Bipyramidal crystals are also seen. Also as crusts, micaceous, foliated and earthy.
Fracture is uneven.
Streak is a pale green. Radioactive, non-fluorescent and cleavage sheets are not bendable but are in fact brittle. Associated Minerals are barite , fluorite , olivenite , brochantite , scorodite , heinrichite , mixite , walpurgite , uraninite and other uranium minerals. Best Field Indicators are color, crystal habit, non-fluorescence, radioactivity, associations especially with arsenic minerals and brittle cleavage sheets.