AN 18TH CENTURY ROSE-CUT DIAMOND HALF-HOOP RING with fluted back and openwork shoulders to the channelled hoop, circa 1770, finger size L 1/2 ; a George IV emerald and diamond cluster ring with pearl centre and beaded gold mount (small diamond and detail to one shoulder missing), circa 1830, finger size M 1/2, and a late Victorian pearl and rose-cut diamond twin-heart ring with ribbon bow cresting and gold hoop, circa 1900