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