Chrysocolla - (Cu,Al)₂H₂Si₂O₅(OH)₄·nH₂O

Habit: Blue, blue green or green; brown to black when impure. Crystals very rare and rarely acicular, in radiating clusters; also fine fibrous, botryoidal or earthy; commonly cryptocrystalline, opaline or enamel-like. Vitreous, porcelaneous or earthy luster; translucent to opaque. Light green streak.

Environment: Occurs in oxidized portions of many copper deposits, commonly associated with other secondary copper minerals.

Etymology: The name was first used by Theophrastus in 315 bce and comes from the Greek chrysos, meaning "gold," and kolla, meaning "glue," in allusion to a material used to solder gold that may have been this mineral.