Star sapphire and diamond coronet cluster ring. Set to the centre with an oval cabochon natural unenhanced star sapphire in an open back rubover claw setting with an approximate weight of 17.00 carats, encircled by a single row of eighteen round eight cut diamonds in open back grain settings with a combined weight of 0.50 carats, flanked on the shoulders by eight rectangular baguette cut diamonds in open back channel settings with a combined weight of 0.40 carats. The total approximate diamond weight is 0.90 carats, to an impressive cluster design with scrolling gallery, open backholing and fine detailing to the openwork shoulders, terminating in a slim D-shape shank. Marked platinum and iridium, American, circa 1930.
