Queen Mary of Denmark has added a new tiara to her rotation. The wife of King Frederik wore Queen Alexandrine's sapphire jewel for the first time on Monday evening. The Queen dazzled in the newly designed headpiece at the state banquet that she and her husband hosted in honor of the President of Vietnam's state visit to Denmark.

The tiara's appearance on October 19 was its first since being reimagined "in close collaboration" with Mary. It can now be worn as a tiara, necklace or brooch. 

The jewelry piece, acquired by the Royal Collection in 2024, was originally a wedding present to Princess Alexandrine, later Queen Alexandrine, in 1898 and has been worn by several generations of royal families, per the Danish Royal House.

"Along the way, the piece of jewellery has been continuously redesigned and adapted to keep up with the changing fashion and usage of the time," the Royal House said in a press release. "The Royal Collection acquired the piece of jewellery from a private owner in 2024. Together with jewellery designers Diana Holstein and Hanan Emquies, the Queen, in close collaboration with the Royal Collection, has helped to give the piece of jewellery a new, fully reversible design. A design that respects the piece's history and special tradition and makes it usable today."

Mary has previously collaborated with the Royal Collection to transform a necklace into a tiara, the Rose Stone Diadem, which she wore to a gala dinner held at Christiansborg Palace in December 2024. At the time, the Royal House stated: "With the creation of the new frame, the Queen and the Royal Collection are resuming the old tradition of adapting the crown jewels to the demands and needs of the time. In many ways, this is paving a new path for the Danish crown jewels, uniting the different traditions that have surrounded these four iconic jewelry sets – a path between revitalization and continuity."

It was also noted that Danish Queens have "each left their mark on the historical crown jewels through major and minor changes. With changes in locks and new ways of combining, the jewelry sets have been updated and thus made their own - always with respect for history and based on a desire to increase the usefulness of the jewelry sets."

The redesigned Queen Alexandrine's sapphire jewel complemented Mary's navy ensemble at Monday's state banquet held at Christiansborg Palace. The royal mom of four teamed the piece with a design by Jesper Hovring and her hair styled in an elegant updo.

The tiara wasn't the only first at the state banquet on Monday. Mary and Frederik's eldest child, Crown Prince Christian, made his state banquet debut at the event, just four days after celebrating his 21st birthday. The heir to the Danish throne looked dashing dressed in the red gala uniform of the Royal Life Guards and the Grand Commander's Cross as he joined his mother and father at the banquet.