Vintage Emerald-Cut Smoky Quartz or Glass Cocktail Ring

This is a vintage cocktail ring featuring a large, prominent emerald-cut center stone in a deep amber or smoky brown hue, likely smoky quartz or high-quality faceted glass. The stone is set in a yellow gold-toned metal mounting, possibly 10k or 14k gold given its vintage aesthetic, or a high-quality gold plating. The setting utilizes a four-prong arrangement where the prongs are discreetly folded over the corners of the rectangular stone to maximize visibility of the facet work. The band appears to have a split-shoulder or decorative shank design which is characteristic of Mid-Century Modern or late Art Deco influence, typically dating from the 1940s to 1960s. The stone displays sharp, clean faceting with a high degree of transparency and moderate internal depth of color. Condition-wise, the stone shows minor surface wear consistent with age, specifically light abrasions on the table facets and slight rounding of the facet junctions. The metal shows a soft patina and slight tarnish in the recessed areas of the setting. There are no immediately visible maker's marks or hallmarks in the provided perspective, though such stamps would typically be located on the interior of the shank. The overall craftsmanship suggests a well-made decorative piece intended for formal or evening wear.