One of the most luminous aquamarines in the Norwegian royal vaults is set in a lovely brooch worn by Crown Princess Mette-Marit. Today, we’ve got a little bit of backstory on the piece.

The brooch features a beautiful faceted sea-green aquamarine set in an intricate diamond surround. The diamond elements of the brooch seem to date it to the late Victorian era or Edwardian era.

Here’s another look that gives you a good idea of the brooch’s color, setting, and dimension. The piece reportedly first belonged to Queen Maud of Norway, and it was worn by both Maud and later by Queen Sonja. The design of the setting easily dates it to the early years of Queen Maud’s marriage.

Today, the jewel is worn exclusively by Crown Princess Mette-Marit. She began wearing the piece in 2012, which makes me wonder if it was an anniversary present. (She and Crown Prince Haakon celebrated their tenth wedding anniversary in August 2011.) In January 2012, she paired the brooch with her Diamond Daisy Bandeau and Crown Princess Martha’s Silver Wedding Earrings for a banquet during the Ruby Jubilee celebrations for Queen Margrethe II of Denmark in Copenhagen.

Four years later, she wore the same combination of jewels for a set of new official portraits, taken to mark the Silver Jubilee of her parents-in-law, King Harald V and Queen Sonja of Norway, in January 2016.

Crown Princess Mette-Marit generally reserves this brooch for gala occasions, diplomatic events, and sometimes for more formal daytime events. In April 2013, she wore it for a water pageant in Amsterdam following the inauguration of King Willem-Alexander of the Netherlands.

And in May 2016, she wore the brooch in Stockholm for the christening of Prince Oscar of Sweden, the son of Crown Princess Victoria and Prince Daniel. Mette-Marit is one of the little prince’s godparents.