The Pigot Diamond, also sometimes called the Pigott Diamond, the Lottery Diamond, or the Great Lottery Diamond, was a large diamond that originated in India in the 18th century and was brought to England where at the time it was the largest diamond in Europe. It remained in Europe for half a century, changing hands several times until it was sold to the ruler of Egypt in the 1820s. What happened to it after that is unknown, inspiring a two-century mystery.