diamonds in the rough
Diamonds offer a unique view of the world underground -Representational ImagePixabay

Calcium silicate perovskite is one of the Earth's most abundant minerals, but it has never been found at the surface, until now.

It is found deep within the Earth's mantle and is known to be too unstable to exist on the surface. However, scientists were able to recover a small bit of the mineral, trapped inside a diamond, reports

"Nobody has ever managed to keep this mineral stable at the Earth's surface," said Graham Pearson, a professor in the University of Alberta's Department of Earth and Atmospheric Sciences and Canada Excellence Research Chair Laureate.

Found in abundance deep in the Earth, at about 700 km from the surface, it has never been seen on the surface. "Based on our findings, there could be as much as zetta tonnes of this perovskite in deep Earth," he added.

One of the only ways to actually keep it stable in the surface will be to trap it inside an almost indestructible and strong container like a diamond, he explained. The diamond from which the compound was extracted came from a South African mine at a depth of just a kilometer.

Cullinan Mine in South Africa, said Pearson, not only produces the most commercially viable diamonds, but also the most scientifically interesting ones, because they offer a unique look into the deep recesses of the planet that are mostly unreachable.

The pressure that this particular diamond would have had to undergo before it formed could have been equivalent to about 240,000 atmospheres, he said. While most diamonds are formed at a depth of about 150 to 200 km, this one possibly formed at a depth of at least 700 km, notes the report.

Pearson went on to explain how diamonds have a unique way of showcasing what is happening deep inside the Earth, adding, "The specific composition of the perovskite inclusion in this particular diamond very clearly indicates the recycling of oceanic crust into Earth's lower mantle. It provides fundamental proof of what happens to the fate of oceanic plates as they descend into the depths of the Earth."

Another major discovery made in 2014, also involving diamonds, was finding ringwoodite, which is the fifth most abundant mineral on Earth. It proved that there are large reservoirs of water in silicate rocks deep inside the mantle.