Cupric sulphate is a chemical compound that is also known by several synonyms. These synonyms are often used interchangeably to refer to the same substance. One common synonym is copper sulphate, which is derived from the fact that the compound contains copper. Other synonyms include blue vitriol, bluestone, and copper sulfate pentahydrate. Blue vitriol is an ancient Greek term that refers to the blue colour of the crystals formed by the compound, while bluestone is a traditional name for the compound used in various applications. Regardless of the synonym used, cupric sulphate is a widely used chemical compound with numerous industrial, commercial and agricultural applications.