Bague au firmament
A superior example of a bague au firmament ring, circa 1780. 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. Here the high cart gold decorative shank supports a plaque of vibrant cobalt blue glass, surmounted by rose-cut diamonds, within a surround of rose-cut diamonds. The ring is size is size O and 1/2 [US 7 and 1/4] and the head of the ring measures 1 and 1/3 inches by 3/4 of an inch. Immaculate, gorgeous ring.
18th century designs for bagues au firmament
detail from a portrait of Marie Antionette wearing bagues au firmamemtn