Wikipedia
Imperial State Crown
The Imperial State Crown is one of the Crown Jewels of the United Kingdom and symbolises the sovereignty of the monarch. It has existed in various forms since the 15th century. The current version was made in 1937 and is worn by the monarch after a coronation ceremony ( St Edward's Crown having been used to crown the monarch) and during his or her speech at the annual State Opening of Parliament. It contains 2,901 precious stones, including Cullinan II – the second-largest clear cut diamond in the world.