Dating cameo jewelry
In cheaper modern work, shell and glass are more common.
For example, thinning the top black layer on a three-layer stone changes its color to shades of brown.
Originally, and still in discussing historical work, cameo only referred to works where the relief image was of a contrasting colour to the background; this was achieved by carefully carving a piece of material with a flat plane where two contrasting colours met, removing all the first colour except for the image to leave a contrasting background.
Today the term may be used very loosely for objects with no colour contrast, and other, metaphorical, terms have developed, such as cameo appearance.
The visual art form of the cameo has even inspired at least one writer of more recent times, the 19th-century Russian poet Lev Mei, who composed a cycle of six poems entitled (Cameos, 1861), as reflections on each of the Roman rulers from Julius Caesar to Nero.
In 1852 Théophile Gautier titled a collection of his highly polished, lapidary poems Emaux et Camées (Enamels and Cameos).