Men's White Metal Ring with Dark Gemstone

The item appears to be a men's signet-style ring, likely crafted from a white metal such as sterling silver, white gold, or possibly platinum, given its somewhat dull, grayish luster and lack of significant tarnish, though the material cannot be definitively confirmed from the image. The ring features a single, prominent, dark-colored gemstone, possibly a black onyx, black sapphire, or a simulant, set flush or nearly flush into the top surface within a rectangular or cushion-shaped bezel setting. The stone exhibits a dark, opaque appearance, and its facets are not clearly discernible, suggesting a cabochon cut or a very shallow faceted cut. The metal band is relatively wide and substantial, indicating a masculine design. It appears to have a brushed or matte finish on the shoulders leading up to the stone, contrasting with what might be polished edges. There are visible signs of wear consistent with regular use, including surface scratches and minor abrasions on the metal, particularly on the sides and top surface, which suggest it is not a new item. The overall condition indicates a good, worn state with a modest patina acquired over time. No specific maker's marks, hallmarks, or unique engravings are visible in the provided image. The style suggests it could be from the mid-20th century to contemporary, with a timeless, classic design.