[imagesource: Petra Diamonds]

South Africa’s Cullinan Mine has provided yet another exquisite and rare blue diamond.

This one is the 39,34-carat type IIb blue diamond (pictured above), which was found on April 1 this year.

Petra Diamonds, the company that found the diamond, says it is of “exceptional quality” in terms of both its colour and clarity, and have announced the final sales process, with a showcasing being held in Antwerp, Dubai, Hong Kong, and New York between June and July.

While a price range for the stone has not yet been set, the UK-based mining firm can confirm that high-quality blue diamonds like this one usually fetch the highest values.

For example, there was Petra’s Blue Moon of Josephine diamond, which was cut from a 29-carat rough blue diamond and sold for $25,6 million (around R350 million at current exchange rates) in 2014 according to Business Insider.

The following year, after being cut, polished, and mounted, which reduced it to a 12-carat gem, it sold for $48,5 million (about R660 million), according to SA People.

The figure that the Blue Moon of Josephine diamond was sold at corresponds to a price of $4 million per carat, which remains the world record price per carat ever paid for a diamond.

But this new 39,34-carat type IIb blue diamond could end up breaking that record.

Type IIb diamonds are the rarest of all the classes, accounting for just 0,1% of the world’s natural diamonds, and have no nitrogen “impurities”.

Type IIb blue diamonds are so rare that their age has not been established, noted Petra.

They are also terribly difficult to excavate.

By studying the minerals trapped inside these diamonds, researchers can tell that they are amongst the deepest-formed diamonds ever found, created at depths of around 500 kilometres below the Earth’s surface.

The blue colour comes from boron that has been linked to seawater, which suggests that these diamonds are a part of some rocks recorded to have been transported from the ocean floor to the lower mantle by tectonics plate.

As the life of a diamond goes, they were formed under conditions of extreme pressure and temperature.

Cullinan Mine, situated near the Magaliesberg mountain range, is the world’s richest spot for rare blue diamonds.

It is the birthplace of the 3,106-carat Cullinan diamond, which was cut to form the 530-carat Great Star of Africa as well as the 317-carat Second Star of Africa – the two largest diamonds in the British Crown Jewels.

The largest cut diamond in the world, the Star of Africa, is set as the main stone in the majestic Sceptre with the Cross:

Image: Cape Town Diamond Museum

The second Star of Africa is placed in prime position, front and centre of the glorious Imperial State Crown:

Image: Cape Town Diamond Museum

Dazzling.

[sources:businessinsider&sapeople]