Napoleon's death mask is cast in bronze. The original cast was created 40 hours after his death in 1821.   During this era, it was customary to create a death mask for prominent leaders when they died.   

A mixture of wax or plaster was applied to Napoleon's face and removed once it had solidified.   

Subsequent copies were made from this impression by casting them. The origins and current locations of the original cast molds are shrouded in mystery and controversy. https://image.nostr.build/4ee02112ce8545b248f3639fd05367f0b6fa8d7eed883373447bb09b1cf0492e.jpg