An Art Deco sapphire and diamond oval plaque ring, with an Edwardian-cut diamond, in the centre of a decorative openwork cluster of round brilliant and Edwardian-cut diamonds, in millegrain edged rub over and grain settings, superimposed on a surround of invisibly set calibré-cut sapphires, with an eight-cut diamond set in each shoulder, with a scroll pierced gallery below, mounted in platinum, circa 1930. The centre diamond weighs approximately 0.71ct, our opinion of the colour is and our…