Double-strand natural pearl necklace, with Cartier clasp

The two strands composed of 288 natural pearls graduating in size from 8.4 to 1.8 mm., completed by a detachable Art Deco lozenge-shaped clasp of buckle design, circa 1925, signed Cartier, London, set with old European-cut diamonds, the center with a single rectangular diamond, altogether weighing approximately 3.25 carats, mounted in platinum, lengths approximately 21 and 23 inches. Together with a pin attachment to wear the clasp separately as a brooch. 

Accompanied by GIA report no. 15226544 stating that the pearls are natural.