Art Decodiamond and platinum ring, French, circa 1930. A platinum ring set with one central round old cut diamond in a rubovercollet setting set into a heavy square bezel and encircled by a single row of twelve round old cut diamonds in bead settings, and with eight round old cut diamonds bead set in a single row to top and bottom and graduated from the outer edge, all twenty one diamonds with an approximate total weight of 1.60 carats, above an openwork geometric gallery, and on a tapered flat shank.