Art Nouveau ruby, diamond and plique-à-jour enamel ring. Set to centre with a drop shape natural unenhanced ruby in an open back rubover setting with an approximate weight of 0.50 carats, embellished by thirty five round rose cut diamonds in open back grain and rubover settings with a combined approximate weight of 0.25 carats, to an elaborate cluster design featuring fine openwork details, intricate scrolling bezel, decorated plique-à-jour enamel work and fancy backholing, flanked by gently scrolling shoulders leading through to a solid D-shape shank. Marked yellow gold and platinum, French, circa 1890.
