The shank oval, the concave bezel set with a carnelian intaglio engraved with the bust of an emperor as Pontifex Maximus (High Priest) in profile to the left. The position of Pontifex Maximus was the highest and most important position in the ancient Roman Religion.
cf: there are similar example in the British Museum, Catalogue of Finger Rings, Greek Etruscan Roman in the Department of Antiquities, British Museum, London 1997, pl. XXXIX, no. 1562; Christie’s London sale 7207, October 2012, lot 184 (for similar intaglio); Sotheby’s London, July 1994, The Benzian Collection of Ancient and Islamic Glass, lot 216, p. 112 (for similar glass ring).