Vintage 1930s Oscar Heyman for Gumbiner Art Deco Diamond Sapphire Twist Ring

A breath-taking one-of-a-kind Art Deco diamond and sapphire twist cocktail ring in platinum, designed by Oscar Heyman for David Gumbiner, circa 1930. The ring features a central Old European brilliant-cut diamond four claw-set in an open-back platinum setting, surrounded by a double spiral of channel-set calibre-cut sapphires. Each shoulder is grain-set with five Old Mine-cut and Transitional round brilliant-cut diamonds. Gross weight: 10.56g. The central diamond is approximately 1.27 carats, G/H colour, VS2 clarity. The melee diamonds are approximately 0.40 carats in total, F/G colour, VS/SI clarity. Sapphires approximately 0.82 carats in total.