Antique Art Deco 0.52ct Diamond 18k White Gold Filigree Solitaire Engagement Ring Size 7.5Unique antique Art Deco diamond 18k white gold engagement ring with a finely detailed shank. The Old European cut diamond solitaire is placed in an octagonal setting. The shoulders and shank have impressive milgrain and openwork filigree that transition to hand engraved vines down the band. Marked 18K with the maker's hallmark of the capital letter B in a diamond shaped cartouche. Circa 1920s. Approx. 0. 52ct Old European cut solitaire diamond; 4.