Five Rare Blue Diamonds Discovered at Cullinan Mine

Five Rare Blue Diamonds Discovered at Cullinan Mine. The five blue diamonds recovered at Cullinan, all in the space of one week’s production. (Image: Petra Diamonds.)

Five blue diamonds, of exquisite transparency and brilliance, were recently found in South Africa, their proud owner announced on Wednesday.

Petra Diamonds Limited said they were discovered the same week in its main mine in Cullinan, located about 40 kilometers east of the capital Pretoria.

Each stone is individual, meaning they are not from a larger fractional diamond, and their weight ranges from 9.61 to 25.75 carats.

“Blue diamonds are so rare that there are no official statistics on them,” said Petra in a statement, stressing that it was very “unusual” to find “five high quality stones at the same time”.

The Cullinan mine is the main source of blue diamonds in the world.

The last significant discovery was a 20.08 carat blue gem found at the site in September 2019, which sold for $14.9 million to an anonymous buyer.

Petra said it was "maintaining a flexible approach to sales" for its latest find and "still evaluating the optimal route to market for the stones".

The group, which has three mines in South Africa and one in Tanzania, was battling with debt and falling diamond prices even before coronavirus shuttered the global gem trade.

It warned that the five blue gems, whilst a "positive development", would "not have a material impact on... the required long-term solution to improve the group's capital structure".