Engraving of the Koh-i-noor ('mountain of light') diamond, in its original state, circa 1851. Previously owned by the Mogul emperors, the Persian Shahs and Ranjit Singh, the Lion of the Punjab, it was presented to Queen Victoria by the East India Company in 1850. The diamond was displayed at the Great Exhibition of 1851, where various experts felt it displayed insufficient fire. It was decided therefore to recut the stone. This was undertaken by Guillaume Coster, over 38 days, in 1852 to produce a round diamond of 108 carats. In 1937 the diamond was placed in a crown to be worn by Queen Elizabeth the Queen Mother at the Coronation of King George VI. The crown and diamond now reside at the Tower of London.