Intaglio of the head of the ‘Youthful Hercules’, in profile to the left, with a club over his right shoulder. Inscribed in reverse Greek letters below the neckline: ΓΝΑΙΟΧ (GNAIOS).

There are nine similar carnelian intaglios from the same hand recorded in the 1830 Windsor inventory of jewels of which this is one. All the pieces are after highly popular and frequently copied ancient prototypes and this is a modern copy of a beryl intaglio of the Roman imperial period signed by the Greek gem-engraver Gnaios; spurious inscriptions of the name or initials of famous engravers of antiquity were common practice in the 18th century. They are all similarly shaped and have identical late 18th century mounts.

The intaglio is from the collection of Consul Joseph Smith of Venice. However, whilst the gem was part of Consul Smith’s collection it is unlikely that it was executed in Venice; engravers capable of such high-quality work were found only in Rome. The group may tentatively be attributed to Anton Pichler (1697-1779) or Carlo Costanzi (1703-81). Both were Roman gem-engravers of great repute; Costanzi was particularly famous for his copies after the antique - he is known to have engraved the head of Antinous several times - ‘and none better’ - according to one contemporary.

Text adapted from Ancient and Modern Gems and Jewels in the Collection of Her Majesty The Queen, London, 2008