A strange deposit of pink diamonds formed when the supercontinent separated, a study has revealed

(CNN) — Pink diamonds are extremely rare and highly sought after: a now-closed Australian mine was the source of 90% of the colored gemstones. High-quality polished pink specimens can be sold for tens of millions of dollars. However, the discovery made in the same area could help find new deposits of this jewelry, according to the researchers.

Scientists studying the Argyle diamond deposits in Western Australia, where the mine is located, say they now better understand the geological conditions needed to form pink diamonds and other colored types, according to a study published Tuesday in the journal Nature Communications Journal.

Using lasers to analyze minerals and rocks extracted from Argyle deposits, researchers discovered that the pink diamond-rich deposits formed during the break-up of an ancient supercontinent called Nuna, about 1.3 billion years ago.

The study’s lead author, Dr Hans, said: ‘While the continent that later became Australia remained united, the area in which Argyll is located stretched, even along the scar, creating gaps in the Earth’s crust through which magma shot towards the surface, bringing diamonds. Pink”. Hugo Ollerock, a researcher at the John D. Laitre Center at Curtin University in Perth, Australia, said in a press release.

Pink diamond drilling

Most diamond deposits are found in the middle of ancient continents, in volcanic rocks that transport diamonds quickly from the depths of the earth to the surface.

However, to become a diamond Roses or red, must be subjected to intense forces resulting from the collision of tectonic plates, bending and bending their crystal lattices. more than Brown diamond It is also formed in this way.

At Argyle, this process occurred about 1.8 billion years ago, when Western Australia and Northern Australia collided, causing previously colorless diamonds to turn pink hundreds of kilometers below the Earth’s crust.

But how did these colored diamonds reach the surface? The team of researchers discovered that the Argyle sites are 1.3 billion years old, from when an ancient supercontinent, known as Nuna, was breaking up.

Pink diamonds from the Argyle Diamond Mine were formed when an ancient supercontinent split into pieces, a new study shows. (Credit: Murray Rayner)

Supercontinents, which form when several continents come together to form a single landmass, have arisen several times in Earth’s geological history.

“Using lasers smaller than the width of a human hair on rocks provided by Rio Tinto (the company that owns the mine), we discovered that Argyle is 1.3 billion years old, 100 million years older than previously thought. Which means it may have formed as a result of the breakup of a supercontinent.” Old,” explains Ollerok.

The authors suggested that the breakup of Nuna could have reopened the ancient bend left behind by the colliding continents, allowing diamond rocks to pass through this region to form large diamond deposits.

This chain of events suggests, according to the study, that ancient continental junctures may be important for finding pink diamonds, and may guide the exploration of other deposits.

“Most diamond deposits are found in the centers of ancient continents because the volcanoes that host them are usually exposed on the surface for explorers to find,” Ollerok explains.

“Argyle lies at the junction of two of these ancient continents, and these edges are often covered in sand and soil, leaving the possibility of discovering similar pink diamond-bearing volcanoes, even in Australia.”