RENÉ BOIVIN - 1940S DIAMOND-STYLED BOW RING The top stylises a large-shelled knot highlighted with rose-cut and brilliant-cut diamonds. In the centre are two larger old-cut diamonds. Set in 18K yellow gold and platinum with small brilliant-cut diamonds. Gross weight: 19.27 g. Finger size: 52. The ring is accompanied by a notice from Jean-Norbert Salit. A diamond, platinum and 18K yellow gold knot ring by René Boivin, circa 1940. Gross weight : 19,27 gr. Size : 52. The ring comes with Jean-Norbert Salit expertise.