The royals are known for their excellent collection of brooches, often symbolic heirlooms passed down within the family. However, the brooch Queen Camilla donned for this occasion is a bit of a mystery.

The heart-shaped jewelry was pinned to the center of her chest, encrusted in diamonds with a coronet-topped royal cypher at the center. While the monogram is sadly indecipherable, per The Court Jeweller, the coronet’s presence indicates that it is not a cypher of a monarch—but could be one for another royal title, like a princess or duke.