Color is deep blue to a more rare, blue-green. Luster is vitreous. Specimens are mostly translucent to individual crystals being transparent. Crystal Habits include acicular to fibrous crystals arranged in tufts, layers or radial aggregates. Cleavage is absent.
Fracture is uneven.
Streak is blue. Associated Minerals include quartz , azurite , cuprite , brochantite , caledonite , atacamite , paratacamite , paramelaconite , malachite , cornubite and chalcophyllite , among others. Best Field Indicators are crystal habit, color, associations and locality.