The Stuart Sapphire is a 104-carat (21 g) blue sapphire that forms part of the British Crown Jewels. The early history of the gem is quite obscure, though it probably belonged to Charles II, and was definitely among the jewels that his successor James II took with him when he fled to France in December 1688. From there it passed to his son, James Stuart (the 'Old Pretender') who bequeathed it to his son, Henry Benedict, known later as Cardinal York, who wore it in his mitre.
As the last descendent of James II, the cardinal put the sapphire, along with many other Stuart relics, up for sale. It was purchased by George III in 1807 and returned to the United Kingdom from present-day Italy.
On the Imperial State Crown of Queen Victoria, the jewel took pride of place at the front of the circlet, just below the Black Prince's Ruby. In 1909, during the reign of Edward VII, it was moved to the back of the crown to make way for the 317-carat (63 g) Cullinan II diamond; it still occupies that position in the back of the crown used by Queen Elizabeth II.
The gemstone is oval-shaped, about 3.8 cm (1.5 in) long and 2.5 cm (1 in) wide, and has one or two blemishes but was evidently deemed to be of high value by the Stuarts. At some point a hole was drilled at one end, probably to introduce an attachment by which the stone could be worn as a pendant. On the back is a miniature plaque engraved with a short history of the crown.
- Sir George Younghusband; Cyril Davenport (1919). The Crown Jewels of England. Cassell & Co. p. 57.
- Edward Francis Twining (1960). A History of the Crown Jewels of Europe. B. T. Batsford. p. 187.
- Claude Frégnac (1965). Jewelry from the Renaissance to Art Nouveau. Putnam. p. 109.
- The Imperial State Crown at the Royal Collection.