Minoru was a horse owned by King Edward VII, and it was the first horse owned by the monarch to win the Epsom Derby in 1909.
To celebrate, he commissioned a jewelled scarf pin in a horse-shoe shape, which he wore pinned on the scarves he wore when outdoors.
Red and blue were Edward VII's racing colours, so the pin had rubies and sapphires, with the name Minoru spelled out in diamonds.
People no longer wear scarf pins, but here is a close up of it worn recently by Queen Camilla as a brooch.