Cameo is a general name for all gems cut in relief, in contradistinction to those hollowed out, or intaglios. More particularly, a cameo is a gem composed of several different-coloured layers having a subject in relief cut upon one or more of the upper layers, an under layer of a different colour forming the ground. Eor this purpose the ancients used the onyx, sardonyx, agate, etc. The shells of various molluscs are now much used for making cameos; and they are also imitated on glass and other materials. Research Cameo
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General Information
Research Cameo