Edwardian Amethyst Diamond Gold Platinum Brooch

An Edwardian amethyst and diamond brooch, with a large emerald-cut amethyst, in a yellow gold claw setting, with an eight-cut diamond set millegrain edged surround, with larger old-cut diamonds in rub over settings, in platinum. The back can be removed so it can be worn as a pendant. Estimated total diamond weight 1.50ct.