Prince Jean Christophe isn’t yet married, but I assume the article refers to his fiancée, Countess Olympia von Arco-Zinneberg.
The ring was in a bag, along with identity documents, a computer and bank cards. The bag was stolen from the Prince’s car, which was parked in the sixth arrondissement of Paris, rue Dauphine.
According to Le Parisien, the diamond came from a dismantled tiara that belonged to Empress Eugénie.
The case is now in the hands of the Police Judiciaire.
It is the first time I hear about this historic stone, and I truly hope that the police will be able to retrieve it.