Glyptics: the art of cutting and carving - either in engraving (intaglio) or relief (cameo) - of a wide range of materials from stones to material of organic origin and including also metals and glass.

The study of an engraved gem provides information about the type of material employed and, when possible, also about the origin, the processing techniques, the state of conservation, and right through to assigning the work to a particular artistic or typological style that characterised the various productions in the course of time.