Vintage Antique Estate Oval Black Onyx Ring - Size 6.5 The large, smooth, polished black oval gemstone is a natural black onyx. It is likely from the Art Deco period (1920s–1930s), The intricate leaf and scroll metalwork visible on the sides is characteristic of filigree designs popular during that era. Size 6.5. Measurement of stone in photo: approximately 1.25 in / 3.18 cm long All of my items come from a smoke and pet free home. Feel free to make an offer. :)