Largest diamond in a century unearthed in Botswana

The largest diamond unearthed in more than a century has been discovered at a mine in Botswana. The Lucara Diamond Corp's shares shot up 34 per cent in reaction to the discovery of the 1,111 carat stone.

"The magnificent stone, which originated from the south lobe of Lucara's Karowe Mine, is the world second largest gem quality diamond ever recovered and largest ever to be recovered through a modern processing facility," said the company said a statement.

The precious stone is only second in size to the Cullinan diamond found in a Lucara mine in South Africa in 1905. It was cut to form the Great Star of Africa and the Lesser Star of Africa which are set in the Crown Jewels of Britain.

"The significance of the recovery of a gem quality stone larger than 1,000 carats, the largest for more than a century... cannot be overstated," said William Lamb, Lucara president and chief executive.

The diamond has yet to be evaluated, and mining analyst Kieron Hodgson, told AFP it has "the potential to be one very expensive diamond".

"Valuation will depend on potential inclusions, how it would behave in cutting, optimal shape as well as final colour," he said. "All these things will need to be evaluated prior to bidding."