Congo Diamond Necklace Tiara.

History
The tiara is a convertible necklace, made by Van Cleef and Arpels. It was a wedding gift from the Belgian colony of Congo in 1953 to Princess Joséphine-Charlotte when she married Hereditary Grand Duke Jean.

The tiara can be seen as a wedding tradition, worn by Grand Duchess Joséphine-Charlotte herself as well as Grand Duchess Maria-Teresa, Princess Marie-Astrid and Princess Margaretha on their wedding days.

Worn by
Grand Duchess Joséphine-Charlotte

Grand Duchess Maria-Teresa

Princess Marie-Astrid

Princess Margareth