Star sapphire and diamond coronet cluster ring. Set to centre with an oval cabochon natural unenhanced star sapphire in an open back rubover setting with an approximate weight of 10.00 carats, enriched by a single row of sixteen round old cut diamonds in open back rubover settings with a combined approximate weight of 1.00 carat, to an elegant openwork cluster with scalloped edging and miligrain borders, intricately pierced gallery with fancy open backholing, the inwardly tapered shoulders lead down to to a solid D-shape shank. Marked platinum, German, circa 1920.
