French Art Deco Ceylon sapphire and diamond double row cluster ring

French Art Deco Ceylon sapphire and diamond double row cluster ring in platinum. Set with an estimated 2.80ct round mixed cut Ceylon sapphire with no indication of heat treatment in a millegrain setting, encircled by two rows of round eight cut diamonds in grain settings, to an oval concentric cluster ring featuring open negative space, millegrain borders, pierced scrolling gallery and flanked to either side with tri-split fleur-de-lis shoulders which terminate to a solid shank. Hallmarked platinum, French.