British-based leading global diamond mining business, Gem Diamonds, has revealed that the stone is of outstanding clarity. The stone was found at the Letseng Mine, owned by the company, in Lesotho earlier this week. The clarity and round shape of this gem mean that its worth could be considerably higher than that of another similar sized rough stone from the same mine, which was recently valued at 12 million U.S. dollars.
It is believed that this gem, in its polished state, may fetch tens of millions of pounds. It is estimated to be capable of producing a 150 carat polished gem stone.
A Gem Diamonds spokesman says that initial examination has shown that the white diamond, yet to be named and valued, has a completely flawless centre.
"Preliminary examination of this remarkable diamond indicates that it will yield a record breaking polished stone of the very best colour and clarity," the Telegraph quoted Clifford Elphick, chief executive officer of Gem Diamonds, as saying.
The find is still dwarfed by the Cullinan Diamond which was discovered in 1905, which was the largest gem-quality rough diamond ever found at 3,106 carats.
However, the biggest polished stone produced from that diamond, the 530 carats Great Star of Africa, is a teardrop shape.
The Koh-i-noor is a round cut but at 105 carats it is smaller than the potential size of the new find.
The mine, which was owned by famous diamond company De Beers for many years, has already produced three of the world's biggest diamonds that include the 603 carat Lesotho Promise, the 493 carat Leteng Legacy, and the 601 carat Lesotho Brown.