A rather splendid example of a bague au firmament ring, circa 1780. The high carat gold engraved and ribbed shank supports a plaque of vibrant foiled cobalt blue glass set with large rose-cut diamonds, within a surround of rose-cut diamonds, all diamonds set silver. Such rings, made popular by Marie Antionette, were known as bagues au Firmament [rings of the Heavens], as the celestial blue ground evoked the night sky and the diamonds twinkled like stars. The ring is size Q [US 8] and the head of the ring is 1 and 3/4 inches long and 3/4 of an inch wide. Very comfortable on the finger due its curved shape, exceptional quality and immaculate.