copperas
/ˈkɒpərəs/noun
mass noun
- green crystals of hydrated ferrous sulphate, especially as an industrial product（尤指作为工业产品的）（水）绿矾, 硫酸亚铁。
词源
late Middle English coperose, from Old French couperose, from medieval Latin cuperosa, literally 'flower of copper', from late Latin cuprum （see COPPER1 ） + rosa 'rose', translating Greek khalkanthon.