Image taken Friday Jan. 18, 2014 and made available by Petra Diamonds of a 29.6 carat blue diamond which was recovered at the Cullinan Diamond Mine near Pretoria, South Africa. The stone is described as being of a vivid blue with extraordinary saturation , tone and clarity, and has the potential to yield a polished stone of great value and importance. AP Photo/Philip Mostert - Petra Diamonds JOHANNESBURG (AP) - A mining company says it has found a rare blue diamond in South Africa. Petra Diamonds says the 29.6-carat diamond came from the Cullinan mine, source of some of the world's most famous diamonds. Cullinan lies near Pretoria, the South African capital. Petra Diamonds said in a statement Tuesday that the diamond is a vivid blue with extraordinary tone and clarity, and could yield a polished stone of great value. The Cullinan mine yielded the 530-carat Star of Africa blue diamond that is part of the British crown jewels.