An enamel necklace, 19th century

An enamel necklace, 19th century, designed in the 18th century style as a collier en esclavage, composed of festoons of enamelled gold linking connected to oval portraits in painted enamels, suspending a similar pendant, length 38.5cm, length 9.8cm, clasp with French assay marks for 18ct gold, enamelled portraits and clasp possibly later added, fitted case with ducal coronet