Source : Webster's Revised Unabridged Dictionary (1913)

Chalcanthite \Chal*can"thite\, n. [L. chalcanthum a solution of
   blue vitriol, Gr. ?.] (Min.)
   Native blue vitriol. See {Blue vitriol}, under {Blue}.

Source : WordNet®

chalcanthite
     n : hydrated blue crystalline form of copper sulfate [syn: {blue
         vitriol}, {blue copperas}, {blue stone}]