Queen Consort Camilla will refashion an old crown for the coronation, notably avoiding the use of the Kohinoor diamond that is clouded by colonialist controversy.
Rather than commissioning a new crown, Buckingham Palace said Camilla would wear a modified version of Queen Mary's crown for the coronation of King Charles III in May.
The Queen Mary crown was commissioned for the 1911 coronation of King George V.
It will be the first time since the 18th century that an existing crown will be used in a coronation.
The choice to reuse a crown was made "in the interests of sustainability and efficiency", the palace said.
Some changes will be made to the Mary crown to reflect Camilla's personal style and to pay tribute to Queen Elizabeth II, the palace said.
Notably, the Kohinoor diamond at the centre of a dispute with India will be removed from the crown.
The Cullinan III, IV and V diamonds, which were previously part of Queen Elizabeth's personal jewellery collection, and were frequently worn by the late monarch as brooches, will be inset into the crown.
The Cullinan diamonds have been set into Queen Mary's crown on previous occasions.
Cullinan III and IV were set temporarily in the crown for the 1911 coronation, and the Cullinan V was inserted when the crown was worn as a regal circlet at King George VI's coronation in 1937.
Four of the crown's eight detachable arches will also be removed, the palace said.
The crown was taken off display at the Tower of London for the modification work to be carried out.
Controversy over Kohinoor diamond
The decision against the Queen consort wearing the Kohinoor diamond, worn by Queen Mary in 1911 and the queen mother in 1937, comes amid rumblings about the jewel.
The Kohinoor is among the largest cut diamonds in the world, worth $591 million, and has a long history with the royal family, having been worn on crowns by generations of queens.
It is believed the diamond was taken from India by the East India Company during the colonial era and presented to Queen Victoria in 1850.
The precious diamond has been fought over for centuries, so much so that British royal legend says the diamond will bring bad luck to any man who wears it.
It currently is set in a crown last worn by Charles's grandmother during her coronation alongside King George VI in 1937.
That the diamond remains in the possession of the British royals is, according to the Indian government, a mark of continuing colonialism more than 75 years after India declared independence from British rule.
Since 2000, India's government has repeatedly requested Britain return the Kohinoor.
The royal family claims the diamond is its property, though it acknowledges it "probably" originated in India.
Following the death of Queen Elizabeth last year, Indian Prime Minister Narendra Modi warned that any plans for the Queen Consort to wear the Kohinoor at the coronation would bring back "painful memories of the colonial past".
As is tradition, King Charles will wear St Edward's Crown, which has now returned to public display at the Tower of London following the completion of minor modification work.
ABC/Reuters
