Azurite - Cu₃(CO₃)₂(OH)₂

Habit: Azure blue or very dark to pale blue. Crystals typically complex, with more than 100 forms recorded: tabular short to long prismatic, with wedge-like terminations, or as rhomboidal, lenticular or spherical subparallel aggregates, which may form rosettes; also internally radial stalactitic or columnar aggregates, botryoidal, drusy, earthy or massive. Vitreous to subadamantine luster; transparent to translucent. Light blue streak.

Environment: Occurs in oxidized zones of copper deposits associated with carbonate rocks, and may constitute an ore of copper.

Etymology: From the Persian lazhward, for its characteristic blue color.