The proportions of the modern brilliant cut were developed by a number of cutters, among whom the most influential was Henry Morse, who in 1860 opened the first diamond cutting factory in the United States at Boston, Massachusetts. Other designs have since been introduced, including the 'round brilliant' of Marcel Tolkowsky, whose book Diamond Design (1919) systematically analysed the optics of a diamond to show the best fire and brilliance. The brilliant cut is also used for many other gemstones. Variations continue to be developed, usually in accordance with the designs for standard proportions of Eppler, Scandinavian Diamond Nomenclature (SCAN DN Cut), and the International Diamond Council (IDC).
Source: Diamond Design (1919); History of Diamonds.
