A late eighteenth century 'coque de perle', or 'eggshell pearl,' riviere, each panel carved from nautilus shell and resembling eggshells in curvature and delicacy, each panel set double-sided and framed in 9k gold approximately 0.6 in by 1.0 in, slightly graduated and terminating in a matching push-box clasp, minor damage to two panels on the reverse commensurate with age, length 16.5 in, central drop 1.5 in, circa 1780. 

The most timeless georgian necklace is the riviere, as popular today as it was 300 years ago. Riviere, meaning 'river of light,' was named for the famed lights of the Cote d'Azur, as the diamond riviere resembled the twinkling lights of the coastal towns. Rivieres were made of graduated collet-set matched stones connected as unobtrusively as possible into a continuous line. Silver set diamond rivieres achieved popularity around 1750, but were soon backed in gold to prevent tarnishing. Rivieres of paste or colored stones were often set in gold in closed back settings with colored foil. They frequently included a detachable pendant drop, often in the shape of a cross. With increasing quality of gemstones and diamonds in the nineteenth century, stones were prevalently set 'a jour' or open backed.