Zinc sulfate (ZnSO4) is a colorless crystalline, water-soluble chemical compound. The hydrated form, ZnSO4·7H2O, the mineral goslarite, was historically known as "white vitriol" and can be prepared by reacting zinc with aqueous sulfuric acid. It may also be prepared by adding solid zinc to a copper(II) sulfate solution.
Zn + CuSO4 → ZnSO4 + Cu
It is used to supply zinc in animal feeds, fertilizers, and agricultural sprays. ZnSO4·7H2O is used in making lithopone, in coagulation baths for rayon, in electrolytes for zinc plating, as a mordant in dyeing, as a preservative for skins and leather and in medicine as an astringent and emetic.
Another natural form of this heptahydrate is known as mineral Zinc-melanterite (Zn,Cu,Fe)SO4·7H2O (structurally different from goslarite). Lower hydrates of zinc sulfate are rarely found in nature as minerals: bianchite (Zn,Fe)SO4·6H2O, boyleite (Zn,Mg)SO4·4H2O and gunningite (Zn,Mn)SO4·H2O.
An aqueous solution of zinc sulfate is claimed to be effective at removing moss from roofs. Spraying a mixture on moss will allow the wind to simply blow off the remaining debris; however, it is not recommended for use on lawns as it is as effective at removing grass. Zinc sulfate was once used in home acne remedies.