The Peruzzi Legend

(via Diamond Cuts in Historic Jewelry:1381-1910) Herbert Tillander writes:

The idea that the Brilliant Cut was invented was based on nothing more than armchair speculation by Caire, who wrote in La Science des Pierres Précieuses (1813): ‘C’est par une suite de recherches sur le diamant brut qui avait de la couleur, qu’on parvint à la taille dit diamant recoupé. Les renseignements que j’ai pu me procurer semblent en attribuer la glorie à Vincent Peruzzi, de Venise, qui vivait vers la fin du dix-septième siècle.’ This very tentative and unsubstantiated statement was at once accepted, and repeated verbatim throughout the nineteenth century even by such respected authoritites as the Dutch diamond cutter and trade union leader, Henri Polak. Squares were well-known and highly prized all through the eighteenth century, but it is possible that they were first produced and marketed commercially around 1690, frequently quoted in the literature as the date when the Brilliant Cut was supposed to have been created.

The term Peruzzi Cut has never been used in the diamond trade itself, but has become so firmly established that there is no point in trying to abolish it. It has come to represent absolute perfection. Wilhelm Maier (1949) was full of admiration for its symmetry. He described the central star formation and the facet edges parallel throughout, and added that the balance of the facet edges is the most perfect ever achieved.