Generally, the identifying mark of the maker of an article of jewelry, comparable to the maker's mark on ceramic ware and the decorator's mark on some glassware.
Among the names engraved on some Greek and Roman engraved gemstones are Aulos, Dioskorides, Gnaios, Solon, Sostratos, and Tryphon. Some pieces of Anglo-Saxon jewelry, e.g. Canterbury coin brooch, bear the maker's name.
Modern jewelry often bears the make of the individual designer-make, or of the firm that had it made by its own craftsmen from the design of an employed designer. Often the most effective method of identifying the designer, especially of jewelry made in the 17th/ 19th centuries, is by reference to the many design books that have been left.
Other marks seen on jewelry include a hallmark, patent mark, design registry mark, and trademark.
From: An Illustrated Dictionary of Jewelry, autor: Harold Newman, publishers: Thames and Hudson