Art Deco Ceylon sapphire and diamond ring. Set to centre with an octagonal step cut natural unenhanced Ceylon sapphire in an open back claw setting with an approximate weight of 5.18 carats, flanked by six rectangular baguette cut diamonds in open back rubover settings with a combined approximate weight of 1.00 carats, to a geometric flanked solitaire design featuring millegrain edging, a structured gallery and open backholing, leading to smooth shoulders and flowing through to a solid shank. Marked platinum, numbered '309', English, circa 1925, accompanied by Gubelin Gem Lab report #14037083.
