Petra Diamonds Ltd reported the discovery of a 122.52-carat blue diamond at its Cullinan mine in South Africa.
"The stone will require further analysis in order to assess its potential value and upon completion of this process, Petra will be in a position to evaluate its optimal route to market.
"The diamond will therefore not be sold before the end of the company's current financial year (30 June 2014).
"The rarity of a blue diamond of this magnitude sets it apart as a truly significant find.
"Cullinan is known as the world's most important source of blue diamonds and since Petra acquired the mine in 2008, it has continued to produce a number of exceptional blues."