Colour change Ceylon star sapphire and diamond coronet cluster ring. Set to centre with a oval cabochon natural unenhanced Ceylon blue/purple colour change star sapphire, blue in daylight and purple in incandescent light in an open back rubover setting, with an approximate weight of 5.50 carats, encircled by thirteen round old cut diamonds in open back rubover settings with a combined approximate weight of 1.65 carats, to an elegant coronet cluster design featuring polished edges, an intricately pierced scalloped gallery and fancy shape open backholing, flanked by tapered openwork shoulders with cheniers and flowing down to a solid flat shank. Marked platinum, English, circa 1915, accompanied by a Gem & Pearl Laboratory report #17977.
