Goslarite is a mineral composed of hydrated zinc sulfate, usually found in copper and zinc deposits. Its chemical formula is ZnSO4·7H2O and it forms green or yellowish-green crystals. Synonyms for goslarite include zinc vitriol, zinc sulfate heptahydrate, and green vitriol. Zinc vitriol gets its name from its color and was commonly used in the production of ink, dyes, and pigments. Zinc sulfate heptahydrate is the scientifically correct name for goslarite, while green vitriol is a more colloquial term. Whatever you choose to call it, goslarite remains an important industrial and chemical substance.