The crown of French Empress Eugenie was left crushed after being dropped by fleeing thieves during the raid at the Louvre last October - but is nearly intact and can be fully restored, the museum has said.
Raiders stole an estimated 88 million euros (£76m, $104m) in jewels, but left the diamond-studded headpiece belonging to the wife of Napoleon III on their escape route.
The museum has issued the first photographs of the crown since the theft, saying it had been left badly deformed after the thieves tried to remove it through a narrow hole they sawed in its glass display case.
The crown is missing one of eight golden eagles that adorned it but retains its 56 emeralds and all but 10 of its 1,354 diamonds.
The museum stated the crown would be restored to its original state without the need for reconstruction. An expert committee led by the museum's president Laurence des Cars has been selected to supervise the restoration.
The heist, which took place on 19 October, involved a gang using a stolen vehicle-mounted mechanical lift to gain access to the Galerie d'Apollon (Gallery of Apollo) via a balcony close to the River Seine. Two of the thieves cut through a window with power tools, threatened the guards, evacuated the area, and cut through the glass of two display cases housing jewelry from French royalty.
Prosecutors reported the thieves were inside for less than four minutes before escaping on scooters. While four suspects have been arrested, the mastermind behind the raid remains at large. Other missing items from the museum include a diamond-studded tiara that belonged to Eugenie and various necklaces, earrings, and brooches.
