Men's Black Onyx and Diamond Two-Tone Signet Ring

This is a men's ornate signet-style ring, likely constructed from 10k or 14k yellow gold with white metal accents (potentially rhodium plating or white gold). The central feature consists of a rectangular black onyx tablet inlaid with a white metal four-pointed star or kite-shaped setting containing a single round-cut diamond. The ring face is framed by a row of five additional round-cut diamonds set in a white metal channel along one corner of the square bezel. The shoulders of the band exhibit a heavy, textured 'brick' or geometric stamped pattern that lends a masculine, mid-century aesthetic. Based on the design, it likely dates to the late 20th century (1970s-1990s). The piece shows moderate signs of wear consistent with regular use, including surface abrasions on the metal, minor scratches on the onyx face, and a visible buildup of skin oils and debris around the settings and textured areas. The craftsmanship suggests a commercial production piece rather than a custom-made high-jewelry item. No maker's marks or hallmarks are visible in the provided image, though they would typically be found on the interior of the shank.