James Tassie (1735-1799) was a Scottish gem engraver, who worked with Dr Quin to develop and opaque glass that could be molded into intaglios. His work was prolific, making mostly classical subjects and portraits of famous people. Catherine the Great of Russia bought many of his intaglios for her collection. His son and grandson carries on with the art, but only James' work was mark T or F. This intaglio is signed F, and is a portrait of Achilles. the Greek warrior, identified by the lizard on his helmet. The intaglio is incredibly detailed seen under the loupe. The pendant is amethyst colored glass and framed in 14K yellow gold (acid tested). There is a small chip at the top of the intaglio in the back and is covered by the leaves of the frame. The Victorian book chain is mid 1800s, gold filled and 20" long and 5/16" wide. So rare. International by EMS and insured only.