According to Royal Central:
At the centre of the cross on the front is one of the oldest pieces of jewellery in the royal collection: The Black Prince’s Ruby, which was gifted to the Prince of Wales (also known as The Black Prince) in 1367 by Pedro the Cruel, the King of Castile.
The cushion-shaped brilliant diamond set on the front band…was cut from the Cullinan Diamond. At the back, a sapphire known as the Stuart Sapphire is set.
Among the jewels included in the Imperial State Crown… are 2,868 diamonds, 17 sapphires, 11 emeralds, 269 pearls, and 4 rubies.
To read the entire article on Royal Central, please click here.
