Gold and black stone cocktail ring (not authenticated)

This piece features a prominent, rectangular black stone, possibly onyx or black tourmaline, set in what appears to be a yellow gold mounting. The central stone is faceted with a flat top and angled edges, securely held by prong settings. The metal bezel surrounding the stone is detailed with a twisted rope texture, and the broad shoulders of the band exhibit a distinct fluted or scalloped ribbed pattern. The band tapers slightly toward the back. The item shows moderate surface wear and patina consistent with age and previous use, including minor scuffs on the metal and stone. There are no clearly visible maker's marks, stamps, or hallmarks discernible from this photographic angle; the identification rests purely on physical characteristics and visual style. The overall design aesthetics are consistent with mid-century or retro jewelry styles, though age and material composition remain unverified without physical testing.

Based on what I can see in the photograph, this cocktail ring features a prominent, rectangular black stone set in a yellow gold mounting with a twisted rope bezel and fluted shoulders. The design aesthetics suggest a mid-century or retro jewelry style. However, I can't verify from a photo whether the metal is solid gold or gold-plated, nor whether the black stone is genuine onyx, black tourmaline, or a synthetic substitute. There are no clearly visible maker's marks or hallmarks discernible from this visual angle. My estimated value range of $450 to $750 assumes that the materials are consistent with the visual presentation—specifically that the mounting is solid yellow gold and the stone is a natural dark gem. This range reflects typical market demand for vintage mid-century cocktail rings of similar scale and style. To establish a more precise valuation and resolve the uncertainties, an in-person examination would be required, including physical testing of the metal purity, gemological testing of the stone, and a search for obscured stamps or hallmarks. If physical testing reveals the piece to be a later reproduction, a modern replica, or gold-plated base metal rather than solid gold, the market value would decrease significantly, likely falling into the $75 to $150 range.