Cupric Sulphate

Cupric Sulphate (sulphate of copper, blue vitriol), $\backslash text\{CuSO\}\_4$, occurs native in veins of copper and iron pyrites, and is manufactured on a large scale by gently roasting native copper sulphide (copper pyrites), when oxygen is absorbed from the air, the anhydrous sulphate thus obtained being dissolved in water, and from this solution the salt as found in commerce crystallises out. The crystals are large, transparent, and have a fine blue colour. They are much used by the dyer and calico-printer, in electroplating, and in the preservation of organic materials.