Petra finds 39-carat blue diamond at Cullinan mine

South Africa’s Petra Diamonds has found yet another big rock at its iconic Cullinan mine, a 39.34 carat Type IIb gem said to be of “exceptional quality” due to both its colour and clarity.

The miner didn’t indicate the diamond’s potential value but said it would sell it in a special tender.

Cullinan is known as the world’s most important source of blue diamonds, as well as being the birthplace of the 3,106-carat Cullinan diamond, which was cut to form the 530-carat Great Star of Africa.

The operation also yielded the 317-carat Second Star of Africa. They are the two largest diamonds in the British Crown Jewels.