Color is a bright emerald green or dark green to almost black. Luster is vitreous. Crystals are transparent to translucent. Crystal Habits include small tabular crystals and acicular or fibrous crystal aggregates that form into coatings and tufts. Also found in veins and as reniform, massive or granular specimens.
Cleavage is perfect in one direction and poor in another.
Fracture is uneven. Streak is pale green. Associated Minerals are limonite , brochantite , cuprite , malachite , gypsum , chalcanthite , atacamite and azurite . Best Field Indicators are crystal habit, associations, hardness, cleavage, non-reaction to hydrochloric acid and color.