Marquise-cut stone cocktail ring

This piece appears to be a vintage cocktail ring featuring an elongated marquise or navette-shaped faceted blue stone centrally flush-set or bezel-set within a smooth, highly polished metallic mounting. The ring exhibits a distinct pointed, boat-shaped silhouette characteristic of mid-20th-century costume jewelry designs, possibly dating from the mid-century era, though without visible hallmarks or stamps, its exact age and composition remain unverified. The band is simple and rounded, soldered to the sizeable decorative bezel plate. The blue gemstone displays a vibrant cobalt hue with noticeable facet light reflection, though the specific nature of the stone—whether colored glass, synthetic spinel, or natural gem material—cannot be determined from the visual evidence alone. The metal surface shows minor scratches, scuffs, and slight tarnish under magnification, consistent with age and prior wear. The identification rests entirely on the visual observation of its unique geometric shape, construction style, and general aesthetic rather than any maker's mark or documented provenance.

Based on what I can see in the photograph, this item presents as an elongated marquise or navette-form cocktail ring, consistent in style with mid-20th-century costume jewelry. The central element is a faceted cobalt-blue stone set flush within a broad, boat-shaped metallic bezel atop a simple shank. However, I cannot verify the exact material composition from a photograph alone; whether the mounting is silver, base metal, or plated cannot be determined without physical testing, and the blue stone could be glass, synthetic spinel, or another mineral. The surface displays light abrasions and minor wear commensurate with age. My valuation estimate of $60 to $120 reflects typical market demand for vintage mid-century costume jewelry rings of similar decorative appeal if the piece is assumed to be an unmarked vintage base metal or sterling costume item. If an in-person examination, hallmark inspection, or metallurgical assay were to show that the mount is precious metal (such as high-karat gold or platinum) housing a natural gem, the market value could increase substantially into the several hundreds or more. Conversely, if it is a modern decorative reproduction using inexpensive acrylic or contemporary plated alloy, the decorative resale value would likely be closer to $15 to $30. Formal identification would require physical gemological testing and an in-person inspection of the metal alloy.