A delicate filigree mounting contrasts with the bold lines of black onyx in this antique cocktail ring. The slim 14k white gold band of this dramatic dinner ring has a heart and key design at the shoulders. The elongated mounting of this antique dinner ring holds an octagonal tablet cut black onyx in its scalloped prongs. This 3.0-carat gemstone is centerpieced with a diamond-studded lozenge. The round single cut diamond nestled inside weighs 0.01 carats. Circa 1920.