Roman Gold Ring with Gemstone

3rd century AD. A gold finger ring with flat-section gold hoop, ellipsoid cell to the bezel with inset sardonyx(?) gemstone. Cf. Ruseva-Slokoska, L., Roman Jewellery, Sofia, 1991, item 206, for type. 1.59 grams, 15.44mm overall, 14.88mm internal diameter (approximate size British G, USA 3 1/4, Europe 4.92, Japan 4) (1/2"). From the private collection of a Leeds professional; acquired by gift from his grandfather in the late 1980s-early 1990s.
Condition Report: Fine condition, hoop cracked.