Art Deco diamond and sapphire rectangular target plaque ring in platinum

Art Deco diamond and sapphire rectangular target plaque ring in platinum. Centred with an estimated in a platinum millegrain setting, surrounded by eight calibre cut sapphires in invisible settings and flanked to either side with two vertical rows of round old cut diamonds in grain settings, to a geometric cluster with millegrain settings, openwork gallery and met to either side with raised shoulders which curve to a solid shank.