Vintage 925 Sterling Silver Black Onyx Modernist Statement Ring Size 7.5 Signed

Striking vintage modernist statement ring featuring a large glossy black faceted stone believed to be black onyx, set in a substantial sterling silver mounting.  The bold rectangular/cushion-shaped stone features checkerboard-style faceting that produces dramatic geometric reflections. Wide polished silver sides give the ring a clean architectural modernist appearance.  The interior is marked 925 and bears an additional unidentified maker/pictorial hallmark. Maker and country of manufacture have not been confirmed.  Approximately US size 7.5 as photographed.  Pre-owned vintage condition with minor surface and handling wear consistent with age and use. The highly polished black stone is very reflective and readily shows fingerprints and surrounding reflections in photographs. Sterling silver setting shows light surface wear and age-related patina. No obvious chips, cracks, or major damage observed. Please review the detailed photographs for condition.  Stone has not been professionally gem-tested and is described as believed black onyx based on appearance.