Vintage-style silver-tone cocktail ring with blue stone and marcasite-style accents

This item appears to be a cocktail ring featuring a large, pear-cut center stone in an aquatic blue hue, stylistically consistent with blue topaz, aquamarine, or faceted glass. The center stone is held by multiple prongs within an oval or teardrop-shaped halo setting. This halo, along with a portion of the shank, is encrusted with small, metallic, rose-cut stones consistent with the appearance of marcasite. The metal has an oxidized or antiqued silver-tone finish with visible patina and darkening in the crevices, which is typical of sterling silver or silver-plated alloys. The ring’s design is consistent with Art Deco revival or mid-to-late 20th-century costume jewelry styles. There are no visible hallmarks, maker's marks, or metal fineness stamps legible in the image to confirm the material composition or manufacturer. The construction shows some signs of age and wear, including surface scratches and tarnish on the metal. The identification is considered a hypothesis based on visual stylistic features alone, as physical testing of the stone and metal is required for a definitive material analysis.

Based on my visual analysis of the provided image, I have examined this vintage-style cocktail ring which displays characteristics of Art Deco revivalist costume jewelry. The piece features a pear-cut blue center stone and marcasite-style accents. While the blue stone is consistent with the appearance of blue topaz or faceted glass, and the metal shows a patina suggestive of sterling silver or silver-plated alloy, I cannot verify the material composition or the maker from a photo alone. No hallmarks or fineness stamps are visible, so I am treating the attribution as a hypothesis based on its stylistic features. The value estimate of $45-$85 reflects the retail market for mid-to-late 20th-century costume jewelry in good condition with minor surface wear. This range assumes the item is sterling silver with a semi-precious stone; however, should physical testing reveal the metal to be a common base-metal alloy and the stone to be molded glass, the value would likely decrease to a range of $15-$30. Conversely, if the piece bears an obscured mark from a notable maker such as Theodore Fahrner or a high-end mid-century designer, the value could increase significantly. Market demand for this 'shabby chic' or 'antique-look' jewelry remains steady among collectors of vintage accessories. To reach a more precise valuation, a physical inspection is required to test the metal's acid reaction, verify the gemstone's refractive index, and conduct a microscopic search for hidden maker's marks or signatures.