Courtesy of the British Museum

Talismanic power. This red jasper intaglio (engraved gem) features a sphinx—the pagan mythological creature with a human head, a lion’s body, and wings—which was supposed to ward off evil. Augustus, the Roman emperor (27 B.C.E.–14 C.E.), used a sphinx in his signet ring at one time. Innumerable rings from antiquity display a design cut into a gem that could be used as a seal. Since this ring bears a pagan symbol, however, it remained prohibited to Christians even after Clement relaxed instructions on gold rings.