An 18th century two-sided carnelian intaglio

An 18th century two-sided carnelian intaglio, depicting Hercules slaying the Nemean lion with his club standing vertical behind to one side, the other with gnostic carved inscription, one set within a coiled snake border, mounted in an 18th century gold collector's mount, intaglio 2.7cm high, ring size S

Provenance: Christie's, 29th October 2003, An English Private Collection of Antiquities, ex lot 324, described as 'possibly Graeco-Egyptian, 2nd-4th century A.D.'