This tiara was worn by Princess Margaret, Countess of Snowdon on several occasions (including her wedding)  Poltimore Tiara Designed as a graduated line of cushion-shaped and old-cut diamond clusters alternating with diamond-set scroll motifs, each surmounted by old-cut diamond terminals, to the collet-set diamond line, mounted in silver and gold, circa 1870, 19.2 cm. maximum diameter,…