<P> Originally, the stone was of a similar cut to other Mughal era diamonds which are now in the Iranian Crown Jewels . In 1851, it went on display at the Great Exhibition in London, but the lacklustre cut failed to impress viewers . Prince Albert, husband of Queen Victoria, ordered it to be re-cut as an oval brilliant by Coster Diamonds . By modern standards, the culet is unusually broad, giving the impression of a black hole when the stone is viewed head - on; it is nevertheless regarded by gemmologists as "full of life". </P> <P> Because its history involves a great deal of fighting between men, the Koh - i - Noor acquired a reputation within the British royal family for bringing bad luck to any man who wears it . Since arriving in the UK, it has only been worn by female members of the family . Victoria wore the stone in a brooch and a circlet . After she died in 1901, it was set in the Crown of Queen Alexandra, wife of Edward VII . It was transferred to the Crown of Queen Mary in 1911, and finally to the Crown of Queen Elizabeth The Queen Mother in 1937 . </P> <P> Today, the diamond is on public display in the Jewel House at the Tower of London, where it is seen by millions of visitors each year . The governments of India, Pakistan, Iran, and Afghanistan have all claimed rightful ownership of the Koh - i - Noor and demanded its return ever since India gained independence from the UK in 1947 . The British government insists the gem was obtained legally under the terms of the Last Treaty of Lahore and has rejected the claims . </P> <P> The diamond is widely believed to have come from Kollur Mine, a series of 4 - metre (13 ft) deep gravel - clay pits on the banks of Krishna River in the Golconda (present - day Andhra Pradesh), India . It is impossible to know exactly when or where it was found, and many unverifiable theories exist as to its original owner . </P>

Where is the kohinoor diamond kept in london