CIRCA 2ND-1ST CENTURY B.C.

The ring has a flat, oval bezel with inward-sloping sides and pronounced shoulders tapering into the plan hoop, round in section. Set within the bezel is a convex sardonyx, the natural banding exploited so that the dark brown upper layer, with small red inclusions, is offset by a thin oval band in white.
The central brown layer is engraved with a Nereid riding a hippocamp across the rippling sea. The Nereid clings to the neck of the sea-horse, her mantle draped over her arm and flowing below her in broad u-shaped folds, and clinging tightly to her legs, exposing her sensuous torso. The hippocamp’s head is thrown back, with a fiery mane and coiled serpentine body, its tail rising up and projecting forward.
A Nereid riding a hippocamp was a popular subject on Greek and Roman gems. This example is noteworthy for its large size and the exceptional quality of the workmanship. The same composition is found on a sardonyx cameo in Naples, fig. 68 in C. Gasparri, Le gemme Farnese.