The Imperial State Crown is worn by the Queen at each State Opening of Parliament. It is one of the youngest crowns in the collection and holds a number of much older gems. The crown was remade in 1937 after the previous frame weakened under the weight of the gemstones (!)
Other facts about the Crown Jewels?
The British crown jewels include the massive Cullinan Diamond, the biggest ever gem-quality rough diamond ever uncovered. Discovered in 1905, it weighed 3,106.75 carats.
The Crown Jewels are kept in the Tower of London and are the ceremonial treasures acquired by English kings and queens. They have been used by English kings and queens since 1660 or earlier. The Crown Jewels are part of the national heritage and held by The Queen as Sovereign.
Elizabeth II after her coronation in 1953.