18ct gold, onyx and diamond necklace, Italy, terminating on a lozenge shaped carved black onyx plaque applied to the front with a rope twist lattice pattern highlighted at intervals with claw-set diamonds, surmounted by an openwork geometric motif pave-set with brilliant-cut diamonds supported from a necklace composed of annular onyx plaques between gold and onyx beads, inner circumference 550 mm, Italian workshop registration marks.