Art Deco tourmaline and diamond ring. Set to centre with a natural unenhanced rectangular step cut tourmaline in an open back claw setting with an approximate weight of 1.20 carats, flanked by sixteen round old cut diamonds in open back grain settings with an approximate combined weight of 0.50 carats, to an elegant angular design featuring millegrain borders, a decoratively pierced geometric gallery and open backholing, leading to slightly raised shoulders and flowing through to a solid D-shape shank. Tested 14 carat white gold and platinum, circa 1920.