Queen Camilla is sparkling in another stunning royal headpiece! The Queen, 76, stepped out on Tuesday evening for the state banquet at Buckingham Palace in honor of the President of the

Republic of Korea Yoon Suk Yeo and Kim Keon Hee's state visit to the U.K. She joined King Charles, Prince William, Kate Middleton and other members of the royal family at the glamorous

event. For the first time, Queen Camilla wore the Burmese Ruby tiara, complementing her red velvet evening dress by Fiona Clare. The headpiece was part of Queen Elizabeth's collection

and worn by the late monarch on multiple occasions. Lauren Kiehna, founder of The Court Jeweller, tells PEOPLE: "Camilla's choice of two ruby pieces from the royal vaults was a

jeweler Garrard in 1973, constructed from diamonds and rubies that Queen Elizabeth received as wedding presents. The rubies came from the people of Burma, while the diamonds came from the

deconstructed Nizam of Hyderabad Tiara. Queen Camilla also accessorized with the late Queen Elizabeth's ruby and diamond necklace and earrings from her private collection. While Queen

Camilla has worn many tiaras over the years, she recently had her debut in a historic diadem at the State Opening of Parliament earlier this month. The Diamond Diadem (also known as the

George IV State Diadem) was made for the coronation of King George IV in 1820 — and it's what the monarch wore (along with a large purple velvet cap) on his way to Westminster Abbey for

his crowning ceremony. Since King George IV, the Diamond Diadem has been worn by every British queen, whether they reigned or were consorts: Queen Adelaide, Queen Victoria, Queen Alexandra,

Queen Mary, Queen Elizabeth (the Queen Mother) and Queen Elizabeth. The accessory was closely associated with Queen Elizabeth, King Charles' mother who died in Sept. 2022. She wore the

Diamond Diadem for the first time in public at her first State Opening of Parliament in 1952 (before she was formally crowned at her coronation). At her coronation in June 1953, Queen

Elizabeth wore the headpiece on her way to Westminster Abbey for the crowning ceremony. Queen Elizabeth also wore the diadem on the way to most State Openings of Parliament (though she

swapped it for the Imperial State Crown for the service) and in photographs including those used for British and Commonwealth coinage, banknotes and postage stamps. Since Queen

Elizabeth's death, Queen Camilla has sported a number of accessories closely related to the late monarch. Last month, Queen Camilla visited Mansion House with King Charles to take part

in longstanding traditions marking a new monarch's first visit to the City of London (the historic square mile that joins 32 boroughs to make up Greater London) in their coronation

year. The outing marked a royal first as she made her debut in the Girls of Great Britain and Ireland tiara. Queen Elizabeth wore the accessory numerous times throughout her 70 years on the

throne, including in depictions of her on some British and Commonwealth banknotes and coins. Queen Camilla also sported her first tiara of King Charles' reign for the 2022 state banquet

hosting the President of South Africa Cyril Ramaphosa, a sapphire and diamond tiara that Queen Elizabeth wore for a 2015 state visit with President of China Xi Jinping. King Charles was

also decked out in accordance with the white tie dress code for the state banquet, wearing his decorations, medals, the Garter Star and the Thistle Stars along with the neck order, the

sovereign's badge of the Order of the Bath. He also wore a gift from the Korean president he received earlier in the day: the Grand Order of the Mugunghwa. The order comprises of a

star, neck decoration, sash and badge. King Charles gave a speech starting with a line delivered in Korean welcoming their guests to Britain, which was met with applause. In addition to

praising the nation's efforts on sustainability — with a special shout out to K-pop band BLACKPINK, who attended the banquet — the monarch referenced Korea's influence on pop

culture rivaling the U.K.'s! "Korea has matched Danny Boyle with Bong Joon-ho, James Bond with _Squid Game_ and the Beatles' 'Let It Be' with BTS’s

'Dynamite,' " he said. "Our cultures share a remarkable ability to captivate imaginations across the world, transforming a so-called soft power into a shared

superpower." There was also a new addition to the state banquet reflecting King Charles' reign — at the head table, the glasses at each place setting featured the King's

cypher etched on for the first time. The others still have the late Queen Elizabeth's symbol. CAN'T GET ENOUGH OF PEOPLE'S ROYALS COVERAGE? SIGN UP FOR OUR FREE ROYALS

NEWSLETTER TO GET THE LATEST UPDATES ON KATE MIDDLETON, MEGHAN MARKLE AND MORE! Queen Camilla was also by King Charles' side earlier in the day when they welcomed Korea's president

and first lady at Horse Guards Parade. "She is the yin to his yang," a close palace insider told PEOPLE of the King and Queen's relationship. "She is the type to say,

'It'll all be fine; let's crack on and get on with things.' " Royal biographer Christopher Wilson, who studied the couple in the book _A Greater Love_, added that

Queen Camilla soothes King Charles in a way no one else can. "Her presence reassures him," Wilson said. "Despite all the trappings of majesty, it's cold and lonely at the

top, and it's easy to see the comfort she provides him."