Cameo
a term applied to gems of different colors sculptured in relief. The art of engraving on gems boasts of high antiquity, having been practiced with various degrees of success by the Egyptians, Greeks, and Romans. It was revived in Italy in the 15th century, and is even at the present day cultivated with considerable success. The cameos of the ancients were usually confined to the agate, onyx, and sard, which, on account of the variety of their strata, were better suited to display the artist's talents; but they were also occasionally found executed on opal, beryl, or emerald, emerald, and even on a sort of factitious stone, the obsidianum of Pliny, distinguished by the moderns as the antique paste. One of the most famous cameos is the onyx at present in Paris called the " "Apotheosis of Augustus." It is 1 foot in height, and 10 inches in width. the Vitrum