Paris green

Paris green (copper(II) acetate triarsenite or copper(II) acetoarsenite) is an inorganic compound. As a green pigment, it is also known as Schweinfurt green, emerald green or Vienna green. It is a highly toxic emerald green crystalline powder which, despite its toxicity, has been used as a rodenticide and insecticide, as well as a pigment. It is also used as a blue colorant for fireworks. Paris green is said to range in color from a pale bluish green when ground very finely to a darker green when ground coarsely.