The British royal vaults are packed with tiaras that have been worn for decades and even centuries, but the family’s jewelry collection also includes some modern pieces. One of the most striking of these newer jewels is the dazzling diamond and aquamarine tiara worn by the Countess of Wessex.

The Wessex Aquamarine Necklace Tiara, reportedly made by Collins and Sons, showcases a gorgeous oval-cut aquamarine in a lovely shade of sea green. On either side of the aquamarine, diamonds trail across the piece, set in a modern scrollwork design. The diamond setting echoes cresting waves—a perfect complement to a gemstone associated with the sea—but there’s something sharp and new about the overall design of the piece. Like many modern tiaras, this one pulls double duty: it can also be worn as a necklace.

Sophie debuted the tiara in November 2005. She chose it for a particularly grand and glitzy celebration: the gala held following the enthronement of Prince Albert II of Monaco. Sophie’s collection includes several pieces of jewelry set with light blue and green stones, likely aquamarines as well as blue topazes, and she also wore a necklace and earring set from that group for the gala.

We glimpsed the necklace setting of the tiara for the first time shortly afterward. In March 2006, she wore the necklace in London for a gala dinner supporting ChildLine and Mission Enfance Royal. On this occasion, she wore no other jewelry, letting the necklace take center stage.

In recent years, Sophie has added another aquamarine tiara to her jewelry box: the Aquamarine Ribbon Tiara, which was loaned to her by her mother-in-law, Queen Elizabeth II. But she has also continued to wear the modern aquamarine tiara for royal gatherings. In June 2015, she dazzled in the tiara in Stockholm at the wedding of Prince Carl Philip and Princess Sofia of Sweden. She coordinated the tiara for the event with another blue-green gemstone pendant from her collection.

And in May 2017, she wore the tiara (and the same pendant necklace) in Oslo for the joint 80th birthday celebrations for King Harald V and Queen Sonja of Norway. I’m glad the tiara has continued to be a major part of Sophie’s jewelry rotation. As much as I adore a classic nineteenth-century tiara, I’m always excited to see how modern jewelry designers interpret the form, too.