In this case, the conversion is not so dramatic since it involves only the loss of a few water molecules and therefore a good pseudomorph is likely. The conversion is irreversible and ongoing and all collection specimens of a certain age are partially to totally converted. Fine zeunerite specimens should be stored in a closed container to avoid water loss. 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.