Costanzi, Carlo a very eminent Italian engraver on precious stones, son of Giovanni Costanzi, was born at Naples in 1703. He executed a large number of admirable works, among them a copy of the Medusa of Solon. He brought the art to such a high degree of perfection that he gained a knighthood from the king of Portugal. See Spooner, Biog. Hist. of the Fine Arts, s.v.; Hoefer, Nouv. Biog. Generale, s.v.; Biog. Universelle, s.v.