Don't expect a massive diamond rush, though.
An global team of researchers has used sound waves to estimate the composition of the Earth's upper mantle and they think that about a quadrillion tons of diamonds are buried somewhere over 160 kilometers (100 miles) deep beneath our feet. The study published this week suggests that deep rock layers known as cratons which lie below the centers of most continental plates may be made up of around 2 % diamond crystals. Scientists from MIT - with scholars at ten research universities around the world - have discovered over one quadrillion tons of diamond.
Because we can't just go look at the 100-miles-deep cratons ourselves (the deepest hole we've ever dug didn't even get a tenth of the way), the researchers built a virtual mantle using a computer algorithm and played around with different compositions until they found one that matched up with what they were observing.
Ulrich Faul and his co-workers reached to the before-mentioned results after exploring a baffling seismic anomaly.
What nobody could explain was why sound waves suddenly accelerated when they passed through what is called a "cratonic root".
We all know how sound waves that travel through the Earth help in recording the earthquakes.
"Sound waves move at various speeds through the Earth, depending on the temperature, density, and composition of the rocks through which they travel", MIT explained in a news release.
Researchers from the Massachusetts Institute of Technology (MIT) believe they have found a substantial cache of diamonds hidden in the Earth's interior.
"It's circumstantial evidence, but we've pieced it all together", Faul says.
'One of its special properties is, the sound velocity in diamond is more than twice as fast as in the dominant mineral in upper mantle rocks, olivine'.
"Diamond in many ways is special", said Faul. They noticed that sound waves seemed to speed up under certain parts of the earth's crust, and through a series of tests, they were able to conclude that this could be caused by an estimated sum of 1-2 per cent of diamonds that were part of the cratonic roots.
"Cratons are a tiny bit less dense than their surroundings, so they don't get subducted back into the Earth but stay floating on the surface". Namely, the sound waves were traveling faster than expected through the cratonic roots. Between 150 and 240 kilometres beneath the surface, deep enough to stretch into the Earth's upper mantle. This calculation showed just how much diamond we have, and it is a lot - A quadrillion tonnes. The eruptions carve out geologic pipes made from kimberlite.
Deep in the earth are cratons, masses of rock shaped like upside-down mountains.
"We went through all the different possibilities, from every angle, and this is the only one that's left as a reasonable explanation", Faul said. A meticulous researcher who's not afraid to be controversial, he is nationally known as a journalist who opens people's eyes to the realities behind accepted practices in the care of children.