In history, agate portrait cameos were often gifts from royalty to their subjects. Five-layered onyx Herophiloska Cameo – Roman, 14 to 37 AD This portrait of a man with laurel wreath is probably of Emperor Tiberius.These antique cameos, some more than 2000 years old, are either displayed in museums or are in private collections. The work is signed "Herophilos Dioskourid[ou] ("Herophilus, son of Dioscorides)."Tazza Farnese" An ancient hellenistic bowl made of a very large cameo and purchased by Lorenzo de' Medici during the Italian Renaissance. The colour of the glass was intended by the artist to imitate turquoise. AD 1812 In this cameo the top red-brown layer has been carved into roses. The collector Richard Payne Knight purchased the Flora cameo from an Italian dealer, believing it to be Roman.
This derives from another generalized meaning that has developed, the cameo as an image of a head in an oval frame in any medium, such as a photograph.
especially the various types of onyx and agate, and any other stones with a flat plane where two contrasting colours meet; these are "hardstone" cameos.
) is a method of carving an object such as an engraved gem, item of jewellery or vessel made in this manner.
It nearly always features a raised (positive) relief image; contrast with intaglio, which has a negative image.
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 most famous example of a cameo from the early period is the Portland Vase.
Although occasionally used in Roman cameos, the earliest prevalent use of shell for cameo carving was during the Renaissance, in the 15th and 16th centuries.
This sparked a big increase in the number of cameos that were carved from shells.
Conch shells carve very well, but their color fades over time.
Before that time, cameos were carved from hardstone.