On March 19, Queen Camilla accompanied her husband, King Charles, to a diplomatic reception at Buckingham Palace. For the glamorous occasion, she wore an extra special tiara to pay tribute to her late mother-in-law, Queen Elizabeth II.

Camilla wore a floor-length blue velvet gown by Fiona Claire for the reception, along with pins featuring the royal order of King Charles III, by town and country. Most importantly, perhaps, Queen Camilla chose to wear a tiara rarely seen once owned by Queen Elizabeth.

Aquamarine Ribbon This delicate piece, often called a tiara, "features five large aquamarine set in a diamond ribbon design," according to court jewelers. Camilla's necklace and earrings also featured aquamarine stones, but the outlet reports that they actually come from her personal jewelry collection.

According to court jewelers, Camilla first wore her impressive aquamarine jewelry set, which also featured a bracelet, in 2009. The fact that Queen Elizabeth's tiara perfectly matches the item seems to be a coincidence.

The only photo of Queen Elizabeth 2 wearing an aquamarine ribbon tiara was taken during a royal tour of Canada in 1970-7, the court jeweler reported. The late Queen was seen leaving the Yellowknife City Hall wearing a tiara in a floor-length evening dress and an oversized fringed jacket.

Since then, the tiara has been worn by Sophie, the Countess of Sussex, and now Queen Camilla, on multiple occasions.

The diplomatic reception takes place every year and features a guest list of "over 500 members of the Diplomatic Corps" who are usually welcomed at Buckingham Palace.

Prince William joined Charles and Camilla at the event, but his wife Kate Middleton did not attend. Princess Kate's next big outing will be when she hosts her annual Christmas concert. The Princess of Wales is also reportedly planning a 'rival Christmas party' instead of attending King Charles's Sandringham celebrations.