A chalcedony and diamond dress ring, by Van Cleef & Arpels, 1970s, the front of the ring mounted with a black onyx panel, set between a pair of brilliant-cut diamond lines, to the green chalcedony shoulders, with gold ropetwist decoration, signed VCA for Van Cleef & Arpels, numbered V5408.15, mounted in 18 carat yellow gold, ring size L