Mauboussin cabochon sapphire and diamond ring. Set to centre with a natural unenhanced cabochon sapphire in an open back rubover setting with an approximate weight of 8.40 carats, embellished by twenty six round eight cut diamonds in open back grain settings with a combined approximate weight of 0.40 carats, further adorned with four cushion shape old mine diamonds in open back grain settings with an approximate weight of 0.25 carats, further set with four mixed shape step cut diamonds in open back rubover settings with an approximate weight of 0.20 carats, and accented with three mixed shape natural unenhanced sapphire cabochons in open back rubover settings with an approximate weight of 0.20 carats. The total approximate diamond weight is 0.85 carats to an impressive cluster design featuring intricate openwork with polished edges, a pierced gallery and fancy shape open backholing, leading broad integrated shoulders and flowing through to a openwork shank. Marked platinum, indistinct maker's mark, numbered '0257100', French, circa 1929, accompanied by Gubelin report #22091040 also accompanied by official signed certificate of authenticity from Mauboussin Paris.
