A new study by an interdisciplinary team of researchers used seismic technology (the same kind used to measure earthquakes) to estimate that a quadrillion tons of diamonds lie deep below the Earth's surface.
However, due to the fact that these valuable minerals are deposited at a depth of about 200 km and even deeper, to get them out using modern drilling rigs will not work. Anyone who could extract those diamonds would easily be the richest person to have ever lived, but they are 100 miles under the Earth's surface, much further than the reach of any drill.
"This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it's relatively common", Ulrich Faul, an MIT's Department of Earth, Atmospheric, and Planetary Sciences researcher, said.
As it turns out, diamonds in the Earth are much more common than we thought.
Scientists came up with an estimate of around a quadrillion tons of diamonds by taking into account the total volume of cratonic roots scattered inside Earth.
The study also included researchers from various national and global institutions, including the University of California at Berkeley, Harvard University, the University of Melbourne and the University of Science and Technology of China, among others.
The undertaking to reveal profound Earth jewels started on the grounds that researchers were confused by perceptions that sound waves would accelerate essentially when going through the underlying foundations of old cratons. They are usually cooler and less dense than surrounding rock and result in faster sound waves.
Diamonds have always had the power to capture humans' imagination, being the subject of desire of many.
Thanks to this method, the scientists managed to notice an unusual behavior of the sound waves while passing through the cratons - they sped up more than it was expected.
So they collected virtual rocks, produced using different blends of minerals, to figure how quick solid waves would go through them.
Diamonds are made from carbon, and are formed under high-pressure and extreme temperatures deep in the Earth. That's why the scientists used sound waves to study the part of lithosphere where the presence of diamonds was suspected.
Sound travels through diamond twice as fast as other rocks, so the team of researchers figured there had to be some of the material in the cratons.