Blue vitriol is also known as blue copperas. The word vitriol blue has a strong and clear meaning. Copper sulfate and chemical formula CuSO4.5H2O. The chemical name for vitriol blue is Copper (II) Sulfate Pentahydrate. This salt occurs in the form of a deep rhomboidal prism of deep blue color, with an overly complex taste and done in style.

Similarly, "Green Vitriol" refers to Ferrous Sulphate.