Onyx and diamond pin. The head is set with a rectangular onyx to centre in an open backrubover setting encircled by a cluster of twenty eight round old single cutdiamonds with an approximate combined weight of 0.50 carats in open back grain settings, to an elongated oval form with millegrain border. All set to an open work structure with intricate square backholing. The reverse is fitted with a supportive cross bar with pin, approximately 7.5cm in length. Testedplatinum, marked 'CARTIER NEW YORK', American, circa 1920.