A 29.6 carat blue diamond has been recovered at the Cullinan mine in South Africa, owned by diamond mining group, Petra Diamonds Limited.
According to the company, the newly-found diamond, described as being "exceptional," is an "outstanding vivid blue with extraordinary saturation, tone and clarity."
The stone is said to have the potential to yield a polished stone of "great value and importance."
"Blue diamonds are among the rarest and most highly coveted of all diamonds and the Cullinan mine is the most important source of blues in the world. This stone is one of the most exceptional stones recovered at Cullinan during Petra's operation of the mine," the mining company said in a statement.
Located about 37 kilometres north-east of Pretoria in South Africa, the Cullinan mine is the world's most famous diamond mine.
Cullinan famous diamonds
The mine, which got its name in 1905 after the discovery of the 3,106 carat Cullinan diamond, the largest rough gem diamond ever found, has yielded some of the most renowned diamonds.
The iconic Cullinan diamond forms part of the Crown Jewels in the Tower of London. A 317 carat polished part of it forms the centrepiece of the Imperial State Crown.
Known for a rich source of blue diamonds, the Cullinan mine provided the collection of 11 rare blue stones, including the fancy vivid blue Heart of Eternity (27 carats polished), which were displayed at London's Millennium Dome in 2000.
Other notable diamonds recovered from the mine include the 353 carat Premier Rose, 426 carat Niarchos, 599 carat De Beers Centenary, 755 carat Golden Jubilee and the famous 69 carat Taylor-Burton diamond.
More recent findings include the 507 carat Cullinan Heritage, which was sold for $35.3m (£21m) in February 2010, the highest price on record for a rough diamond.
The mine's latest gift, the 29.6 carat blue diamond is expected to sell at £36m.