Gold and opal screw-back earring

The item presented in the image appears to be a single vintage or antique screw-back earring, likely constructed from yellow gold or gold-plated metal. The primary focal point is an oval-cut cabochon stone, which displays a milky white body with subtle play-of-color flashes characteristic of an opal. The setting features a bezel that snugly holds the cabochon stone. Extending from the bezel is a curved metal shank that leads to a threaded screw mechanism and a small flat circular backing screw, designed to secure the piece onto an unpierced earlobe. The metal exhibits a warm yellow hue with minor signs of age-related surface wear, light tarnish, and gentle patina consistent with vintage costume or fine jewelry pieces from the mid-20th century or earlier. There are no clearly legible maker's marks, hallmarks, or stamps visible in this photograph; therefore, the specific metal purity and manufacturer remain unverified. The overall craftsmanship suggests a classic jewelry design from the Victorian, Edwardian, or mid-century periods, though exact dating is not possible from visual inspection alone. The identification relies entirely on the observed form factor, including the distinct screw-back hardware and the bezel-set oval cabochon.

Based on what I can see in the photograph, the item is presented as a vintage or antique screw-back earring featuring a bezel-set oval cabochon opal mounted in a warm yellow metal. I can observe the classic screw-back hardware characteristic of mid-20th-century or earlier jewelry, along with a milky white opal displaying subtle play-of-color. However, I cannot verify from a photo alone whether the metal is solid gold or gold-plated, nor can I read any specific maker's marks or hallmarks, as none are clearly visible. A physical inspection with specialized testing equipment would be needed to confirm the exact metal purity and the natural origin of the opal stone. My value estimate of $150 to $300 assumes that the attribution to a vintage fine jewelry piece constructed from genuine gold and opal is correct. General market demand for vintage screw-back earrings of this type tends to be modest, appealing primarily to collectors of period accessories. If physical examination reveals the piece to be a modern reproduction, gold-plated base metal replica, or merely made 'in the style of' antique jewelry rather than a period-appropriate fine piece, the market value would likely drop significantly to the $30-$75 range. To establish a more precise evaluation and confirm authenticity, an in-person examination, hallmark verification, and possible gemological testing would be necessary.