GEM

(Lat. gemma.) In Sculpture, a precious stone, used for the purpose of sculpture. The practice of carving gems is of remote antiquity, though it is doubtful whether they were able to cut the diamond or use the emerald and topaz for sculptural purposes. The stones usually selected arc rock crystal of different colours, jasper, chalcedony, onyx, cornelian, and blood stone. Among the Greeks the art was carried to great perfection; but having fallen with the other arts into disuse, its revival was effected in Italy in the 15th century, and modern masters have more than rivalled some of the ancient productions. [s. 505]