Art Deco Diamond & Onyx Ring

Centering an Old European cut diamond weighing app. 0.80ct. (F-G color, SI2 clarity), in an oval carved, onyx plaque with Rose cut diamond (1.0 - 1.5mm) accents at top & bottom and flanking on shoulders, fashioned in platinum and 14k gold. Circa 1920. With vintage ring box. Size 7EGL US69323401D