The Hope Diamond is a 45.52-carat deep-blue diamond from India’s Kollur Mine, celebrated for its unusual blue-violet color, long royal and private ownership history, and scientific importance. Acquired in India by Jean-Baptiste Tavernier in 1666, it was sold to Louis XIV, recut into the French Blue, and entered the French Crown Jewels before being stolen during the French Revolution. It later reappeared in altered form and took its modern name from the Hope family. After passing through Evalyn Walsh McLean and Harry Winston, it was donated to the Smithsonian in 1958. Its boron content, red phosphorescence, and great age have made it valuable to research as well as famous.