St Edward's Crown weighs almost five pounds and features many a semi-precious stone, including rubies, tourmalines, garnets, amethysts and sapphires. Its sheer weight forced a petite monarch to wear it while going about her everyday activities so that on her coronation day she wouldn't be weighed down (literally).
St Edward's Crown is not to be confused with the Imperial State Crown, which Her Majesty uses at the State Opening of Parliament. Both, however, are on display with the rest of the crown jewels at the Tower of London. Below is a breakdown of St Edward's Crown, provided by SavingSpot.
I'm super into this GIF they made, too: