About 1,000 times more common, according to the Massachusetts Institute of Technology.
Deep beneath our feet, in pockets of the Earth's lithosphere that geologists call cratons, there may be more than a thousand trillion (or a "quadrillion") tonnes of diamond, according to a study conducted by a team that includes researchers from MIT and Harvard. These naturally occurring precious minerals are located far deeper than any drilling expedition has ever reached, about 90 to 150 miles (145 to 240 kilometers) below the surface of our planet. These stable chunks of the Earth's crust are shaped like "inverted mountains". Craton is denser and denser than the occult around the planets, and produces sounds that are quite fast.
The researchers decided that the wave propagation inside the craton roots accelerates some of the material inside them.
After this, Faul and others, who used to measure sound velocity through many different types of minerals in the laboratory, used this knowledge to collect the virtual rocks made from various mineral combinations. "One of its special properties is that the speed of sound in a diamond is twice as fast as the main mineral in the upper mantle rock olivine".
"This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it's relatively common", said Ulrich Faul, a research scientist in MIT's Department of Earth, Atmospheric, and Planetary Sciences.
The anomaly that started the project was the discovery that "sound waves tend to speed up significantly when passing through the roots of ancient cratons", MIT News reported.
An worldwide team of researchers approximates that about one to two percent of the Earth's Cratonic roots are composed of diamonds. Earthlings might be perched on plethora of diamonds one quadrillion tons literally.
Scientists now believe the Earth's ancient underground rocks contain at least 1,000 times more diamond than previously expected.
"Diamond in many ways is special", Faul said.
It may be hundreds of years until we develop technology capable of mining the diamonds, but it's nice to know there's a jackpot hidden in the earth.
The study also included researchers from various national and worldwide 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.