Identifying cameos and intaglios
Carved in relief or sunk.
Cameos are carved in raised relief, often in layered stone or shell; intaglios are engraved into the surface for sealing. An intaglio’s design reads correctly in its impression — check it in putty, not just by eye.
Shell cameos are warm, lightweight, and curved on the back, with the layers in soft browns and whites; hardstone cameos (agate, onyx) are cold, flat-backed, and take crisper detail. Wheel-cut work shows rounded channel ends under a loupe.
Glass paste copies — including the celebrated eighteenth-century Tassie casts — reproduce famous gems and are collectable in their own right, but bubbles and molded (not cut) detail give them away under magnification.
Subject and style date the carving; the setting dates the mounting, and the two often differ — ancient gems were remounted for centuries. Record stone, subject, and setting separately.