Britain's 17th-century St Edward's Crown, the centrepiece of the Crown Jewels, has been removed from display to be altered for the coronation of King Charles III, Buckingham Palace said on Saturday.
The solid gold crown, encrusted with rubies, amethysts, sapphires, garnet, topazes and tourmalines, will undergo "modification work" for Charles III's coronation at Westminster Abbey on May 6 next year, the palace said.
The crown is the centrepiece of the Crown Jewels, a large collection of royal regalia housed in the Tower of London that attracts more than a million visitors per year.
It has a purple velvet cap with an ermine band, is just over 30 cm (one foot) tall and very heavy.
It was last worn by Queen Elizabeth II, at her coronation in 1953.
Charles III, 74, will be crowned along with his wife, Queen Consort Camilla.
The ceremony will be followed by a national holiday on May 8.
The crown was made for King Charles II in 1661 to replace a mediaeval crown though to date back to Edward the Confessor.
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