e/Chalcanthum

Information
has gloss	eng: In alchemy, chalcanthum, also called chalcanth or calcanthum, was a term used for the compound blue vitriol (CuSO4), and the ink made from it. The term was also applied to red vitriol (a native sulfate of cobalt), and to green vitriol (ferrous sulfate).
lexicalization	eng: Chalcanthum
instance of	(noun) a salt or ester of sulphuric acid sulfate, sulphate