Edwardian deep Royal Blue Burmese sapphire and diamond cluster ring, circa 1915.

Edwardian deep Royal Blue Burmese sapphire and diamond cluster ring. Set to centre with a cushion shape old cut natural no heat deep Royal Blue Burmese sapphire in an open back claw setting with a weight of 2.75 carats, further set with eight tapered baguette cut diamonds in open back rubover settings with a combined approximate weight of 0.52 carats, further adorned with eight round old cut diamonds in open back grain settings with a combined weight of 1.36 carats. The total approximate diamond weight is 1.88 carats, to an elegant cluster design featuring curving corner claws, a pierced linear gallery and fancy shape open backholing, flanked by angled openwork shoulders with cheniers flowing down to a solid tapering D-shape shank. Marked platinum, circa 1915, accompanied by a Gem Research Swisslab (GRS) report #GRS2017-062595.