Hessonite garnet intaglio set in a gold ring, engraved with the dog-star Sirius, by Johann Lorenz Natter

England, before AD 1754

Copied after an antique gem signed by the Greek engraver Gnaios

Intaglios are cut into the surface of the stone, using a lathe, diamond powder and differently shaped metal drills to abrade the hard material. The tools and method are the same as for cameos, but the image is sunken instead of being in relief. Intaglios were originally used with sealing wax to seal documents. The practice of gem engraving began in classical antiquity and its revival in the eighteenth century aroused great interest in classical gem-engravers, their techniques and subject matter. The demand for ancient gems by scholars and wealthy dilettanti far outstripped the supply, and direct copies were made, sometimes in homage to the original, but more often with the intent to deceive. Some ancient gems were signed, leading to many eighteenth century copies bearing false Greek signatures. Plaster casts of ancient gems were also made; these were often collected in sets with an accompanying catalogue.

Natter (1705-63) published in 1754 a treatise on gem-engraving, in which he described his own attempts to copy the famous classical gem signed by Gnaios. Natter particularly admired the gem for the depth of carving, and published in his treatise an engraving of the gem in profile. It would appear he was equally proud of his own copy, as he signed it 'L. Natter made me' in Greek characters. The hessonite garnet is a rich orangey-red.

C. Gere and others, The art of the jeweller: a cat, 2 vols. (, 1984)

J. Rudoe, 'The faking of gems in the eighteenth century' in Why fakes matter: essays on pr (London, The British Museum Press, 1993)

J. Rudoe, 'Eighteenth and nineteenth-century engraved gems in the British Museum; collectors and collections from Sir Hans Sloane to Anne Hull Grundy', Zeitschrift für Kunstgeschicht, 59 (1996)