George IV State Diadem

The George IV State Diadem, officially the Diamond Diadem, is a type of crown that was made in 1820 for King George IV. The diadem is worn by queens and queens consort in procession to coronations and State Openings of Parliament. The piece of jewellery has been featured in paintings and on stamps and currency. It can be seen in the Queen's Gallery at Buckingham Palace.

George IV commissioned Rundell & Bridge to make the diadem in 1820 at a cost of £8,216. The fee included a hire charge of £800 for the diamonds but there is no evidence they were ever returned to the jewellers. George IV wore the diadem over his velvet cap of maintenance in the procession to his coronation at Westminster Abbey.

The gold and silver frame, measuring 7.5 centimetres (3.0 in) tall and 19 centimetres (7.5 in) in diameter, is decorated with 1,333 diamonds weighing 320 carats (64 g), including a four-carat yellow diamond in the front cross pattée, and two strings of 169 pearls in total along its base. Its design features roses, thistles and shamrocks, the floral symbols of England, Scotland and Ireland respectively, in place of the heraldic fleurs-de-lis usually seen on British crowns.

It has been worn by every queen and queen consort from Queen Adelaide, the wife of William IV, onwards. The diadem was reset with jewels from the royal collection for Queen Victoria. Queen Elizabeth II wore the diadem in the procession to her coronation in 1953, and she also wears it in the procession to and from the annual State Opening of Parliament. When not in use, the diadem is on display in the Queen's Gallery at Buckingham Palace.

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