It's a controversial diamond -- the Agra. This beautiful pink diamond has a long history, with many of the earlier accounts still under dispute.
It is believed that in 1526, the first Mughal emperor, Babur, took the Agra from the raja of Gwalior, whom he had defeated in battle. Babur, it is recorded, wore the diamond in his turban.
By 1844, the Agra was owned by the Charles, the Duke of Brunswick; he is said to have paid a massive sum of franc 348,600 for it. In the 19th century, the Agra was reduced to just under 32 carats to eliminate some black inclusions.
In 1990, the Agra was auctioned at Christie's for pound 4,070,000, making it at that time, the most expensive pink diamond in the world.
Since then, the Agra has again been recut to 28.15 carats.
One of the most famous, and largest, pink diamonds in the world is the Darya-i-Nur, which was also part of the crown jewels of the Mughal emperors.
Information courtesy: De Beers Group, Internetstones.com