Byzantine Ring with Gemstone

6th-8th century AD. A copper-alloy ring with D-section hoop, scooped shoulders, trumpet-style bezel with facetted sides holding cut and polished red circular garnet gemstone; remnants of a small amount of gilding visible. 3.91 grams, 31.50mm overall, 15.93mm internal diameter (approximate size British H, USA 3 3/4, Europe 6.18, Japan 6) (1 1/4"). Property of a London gentleman; acquired on the London art market in the 2000s.
Condition Report: Fine condition.