Art Deco star sapphire and diamond coronet cluster ring, American, circa 1930.

Art Deco star sapphire and diamond coronet cluster ring. Set to centre with an oval cabochon natural no heat star sapphire in an open back rubover and 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 approximate 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 featuring polished borders, a pierced gallery with scrolling motifs, and open backholing, leading to slightly raised shoulders with intricate openwork and flowing through to a tapering D-shape shank. Marked platinum and iridium, American, circa 1930.