Chalcanthite, whose name derives from the Greek, chalkos and anthos, meaning copper flower, is a richly colored blue/green water-soluble sulfate mineral. It is commonly found in the late-stage oxidation zones of copper deposits. Due to its ready solubility, chalcanthite is more common in arid regions.
Chalcanthite is a pentahydrate and the most common member of a group of similar hydrated sulfates, the chalcanthite group. These other sulfates are identical in chemical composition to chalcanthite, with the exception of replacement of the copper ion as jokokuite , or magnesium
Other names include blue stone, blue vitriol, and copper vitriol.