I came across this to share since it's a post-script to the recent Louvre museum royal regalia theft: the crown of Empress Eugenie of the French which was among the items stolen but fortunately dropped by the robbers is now going to be restored to full appearance - although some original diamonds are missing. Presumably - most or all of the other royal jewels were taken apart for the value of the jewel/gold so sadly not surviving in original shape. What I wonder about as a historical aside: why any of the monarchs/spouses left any of these regalia in France when they fled or abdicated? https://www.dw.com/en/louvre-to-fully-restore-empress-eugenies-crown-after-heist/a-75824933