The hydrates, especially the Heptahydrate, are the primary forms used commercially. The main application is as a coagulant in the production of rayon It is also a precursor to the pigment lithopone. Zinc sulfate is used to supply zinc in animal feeds, fertilizers, and agricultural sprays. Zinc sulfate, like many zinc compounds, can be used to control moss growth on roofs It is used as 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