The Imperial Crown of Russia, also known as the great imperial crown, was used by the monarchs of Russia from 1762 until the Russian monarchy's abolition in 1917.
Russian regalia used prior to the creation of the great imperial crown.
1896 image of the crown (at bottom).
After the 1917 revolution, Russia's new rulers debated what to do with the crown jewels. This 1925 photo shows the collection. However, a 1922 album at the U.S. Geological Survey includes photos of four items that are not described in the official 1925 inventory.
The Mysterious Disappearance Of The Russian Crown Jewels