Diamond pendant-necklace, circa 1820

The rivière centering 2 cushion-shaped diamonds weighing 4.36 and 3.30 carats, completed by 45 cushion-shaped diamonds weighing a total of approximately 20.75 carats, supporting a drop-shaped pendant set with 2 cushion-shaped diamonds weighing approximately 1.90 carats and numerous smaller diamonds weighing approximately 1.10 carats, mounted in gold and silver, length 14½ inches, pendant detachable.