Queen Camilla wore the Tiffany & Co. brooch gifted to her by President Trump and First Lady Melania Trump during their visit to the United Kingdom on Wednesday in Windsor.

The brooch, which was worn with the queen consort’s sapphire blue Fiona Clare frock and coordinated Philip Treacy hat, replaced the historic Russian sapphire cluster brooch during the Beating Retreat military ceremony at Windsor Castle. “The brooch is a floral-inspired design, featuring layered gold leaves radiating outward,” Maxwell Stone, a fine jewellery expert from U.K.’s Steven Stone jeweler, told WWD via email.

“At its center, there are four rubies surrounding a central diamond, forming a striking cluster.” Rubies were a significant element to the design of the piece — they are the queen consort’s birthstone. “The piece has a textured, almost sculptural quality to the gold, which gives depth and dimension to the leaves,” Stone said.

During the president and first lady of the United States’ visit to the U.K., Queen Camilla and Kate Middleton both styled sentimental jewelry pieces that evoked homages to the late Queen Elizabeth II and Princess Diana.

“Judging by its design, it has a mid-20th-century style, possibly from the 1950s–1970s, when naturalistic floral brooches in yellow gold with gemstone accents were very fashionable. Wearing the brooch so shortly after receiving it was a thoughtful gesture by Queen Camilla, signaling her gratitude and respect for the gift,” Stone added.

At the state banquet on Wednesday night, Queen Camilla wore the Belgian sapphire tiara, a piece from Queen Elizabeth II’s collection that was worn to state dinners during her reign. For her part, Kate Middleton wore a pair of earrings from the late long-reigning monarch’s vault as well as the Lover’s Knot tiara — a favorite piece of Princess Diana’s during her time as a member of the British royal family.

As for brooches, Queen Camilla has an extensive collection, featuring pieces from Queen Elizabeth’s vault and her own brooches from renowned designers like Van Cleef & Arpels. Brooches often serve as a significant accessory for the royal’s wardrobe, sending subtle messages, honoring members of the British royal family or suiting the occasion or engagement the queen consort attends.