The Sancy Diamond is a 55.23-carat, pale yellow diamond that is likely Indian of origin. This diamond is a shield-shaped cut with two back-to-back crowns.
The known history of the diamond dates back to approximately 1570 and is quite long and colorful. Below is an approximate timeline:
1570: Purchased by Nicolas de Harlay, seigneur de Sancy, the French ambassador to Turkey. Between approximately 1570 and 1605, de Sancy loaned the gem to Henry III of France, who used it to decorate the cap that concealed his premature baldness. He also loaned the gem to Henry IV to use as security for funding his army.
1605: Sold by de Sancy to James I.
1669: Possessed briefly by Charles I and then his third son, James II. James later sold the diamond to Cardinal Mazarin of France, who gave it to the queen.
1828: Purchased by Prince Demidoff. The history is largely unknown prior to this date.
1865: Sold to an Indian prince, who sold it again a year later.
1867: Displayed at the Paris Exposition for a million francs.
1906: Bought, after another period of unknown ownership, by William Waldorf Astor. It remained with the Astor family for 72 years.