Chalcanthite, whose name derives from the Greek, chalkos and anthos, meaning copper flower, is a richly-colored blue/green water-soluble sulfate mineral CuSO·5HO. 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 by either manganese as jokokuite, iron as siderotil, or magnesium as pentahydrite.
Other names include blue stone, blue vitriol, and copper vitriol.
The Collaborative International Dictionary
Chalcanthite \Chal*can"thite\, n. [L. chalcanthum a solution of blue vitriol, Gr. ?.] (Min.) Native blue vitriol. See Blue vitriol, under Blue.
n. (context mineral English) A mineral form of copper sulfate, coppersulfuroxygen4.