Vintage Oval Black Onyx or Glass Cabochon Ring

This item is a vintage-style ring featuring a prominent oval cabochon-cut stone, appearing deep black in color, likely black onyx or a high-quality glass paste. The stone is set into a silver-toned metal mounting, possibly sterling silver or a plated alloy, which exhibits a darkened patina consistent with age. The bezel surrounding the central stone is detailed with a decorative textured or beaded border, often referred to as milgrain or rope-twist detailing, which suggests a mid-20th-century design influenced by Art Deco or Victorian revival styles. The size of the face is approximately 1.5 cm by 1.2 cm, fitting comfortably within the palm of a hand. The metal shows minor surface scratches and significant oxidation in the recessed areas of the metalwork, which highlights the design but also indicates regular wear. No clear maker's marks or hallmarks are visible in the provided image, though such stamps would typically be found on the interior of the band. The craftsmanship appears to be of standard commercial quality for costume or semi-precious jewelry from the 1940s to 1970s. The overall condition is fair to good, with the stone retaining a high gloss and the mounting remaining structurally intact despite the surface tarnish.