Where did the Queen's crown come from?

Queen Elizabeth II has, in the past, opted to use a stylised representation of St.Edward's Crown, made in 1661, which is said to be made of gold melted from King Alfred's Crown and both heavy and difficult to wear. The Imperial State Crown, made in 1937 for King George VI, is worn after the conclusion of the Coronation ceremony when the monarch leaves Westminster Abbey, and also at the annual State Opening of Parliament.