Art Deco Opal, Diamond & Ruby Rectangular Brooch

Art Deco opal, diamond and ruby rectangular brooch in platinum. Centrally set with an oval cabochon cut opal in a compass setting, surrounded by a frame of round single cut diamonds in grain settings and embellished to the corners with four square step cut rubies in rubover settings, to a rectangular plaque brooch with curving claws, polished borders and fitted to the reverse with a secure hinged pin and c-scroll.