Nancy Astor, Viscountess Astor, wearing the Astor Tiara, United Kingdom (20th century; diamonds). The tiara once featured the Sancy Diamond, a pale 55 carat yellow diamond. The 4th Viscount Astor sold the Sancy to the Louvre Museum in 1978. Photographed by Cecil Beaton, 1949. © Plymouth City Council (Arts and Heritage).