According to an international team of scientists, there may be quadrillion tons of diamonds under the surface of the Earth. The deposits are in cratonic roots between 90 and 150 miles below the surface.
“This shows that diamond is not perhaps this exotic mineral, but on the (geological) scale of things it’s relatively common,” said Ulrich Faul, co-author of the study and a research scientist at MIT. They discovered there is much more diamond than they ever thought there could be.
MIT News describes cratons as the oldest and most immovable sections of rock. They are stable chunks of the Earth’s crust and are in the shape of inverted mountains.
The deepest parts are the roots that can reach all the way to the Earth’s mantle. The authors of the study believe the diamonds are in the mantle.
They used seismic data – or recorded sound waves from seismic activity to locate the diamonds. This data helped them measure what the Earth is made of.
Then, the team used 3D modeling to create virtual rocks in a quest to figure out what substances could compose the roots of cratons. Diamonds seemed to foot the bill.
The diamonds matched the velocity of the sound traveling through the roots. They estimated that the roots must be made of 1 to 2 percent diamond.
Using this estimate, and the number of known craton roots, the scientists arrived at their quadrillion-ton estimate. It is 1,000 times more than they first thought.