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.
Cratons are some of the oldest and most immovable sections of rock that lie beneath the centre of tectonic plates.
"Diamonds are a flawless match because they're a little bit more dense, but we don't need a lot of them", said Ulrich Faul, a researcher in MIT's Department of Earth, Atmospheric, and Planetary Sciences and a senior participant in the study.
In making the discovery, Mr Faul and colleagues re-purposed data that already existed to track and measure earthquakes.
But other researchers have suggested some alternative explanations: Garber added perhaps, these cratonic are cooler than the suggestions of rock literature, which means that the rock will harden - and thus, seismic waves will travel more quickly through them - even without the diamonds or eclogite rock.
This technique is how we know the planet has a liquid core, and researchers have continued to refine our conception of the Earth's deepest regions with it.
In a way, Faul says cratonic roots made partly of diamond makes sense. To do this, seismologists on the team first used seismic data from the USGS and other sources to generate a three-dimensional model of the velocities of seismic waves traveling through the Earth's major cratons.
Accordingly, the scientists found that the sound waves velocities when passing through the cratonic roots were similar to those of the sound waves that passed through a mixture of rocks and up to 2% diamonds. A quadrillion tonnes, or about a 1,000 trillion tonnes of diamond is buried below the Earth, but it is out of reach to humans. Molded like rearranged mountains, cratons can extend as profound as 200 miles through the Earth's outside and into its mantle; geologists allude to their most profound areas as "roots".
This method has previously been used to figure out the rocks that make up the Earth's crust and parts of the upper mantle, also known as the lithosphere.
Puzzled by this anomaly, the team set out to uncover exactly what cratonic roots are made of, in order to find out what could be causing sound waves to zoom through them so fast.
Faul said, 'Diamond in many ways is special. 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'.
"We can't get to them, but, nevertheless, there are more diamonds than we ever thought", said Ulrich Fowl (Ulrich Faul), researcher at Massachusetts Institute of technology. In addition, the small fraction of diamond would not affect the overall density of a craton, which has less density than the surrounding mantle.
'Then we have to say, "There is a problem".
"It's circumstantial evidence, but we've pieced it all together", Faul said.
A study published Monday estimates the composition of deep rock layers known as cratons and concludes that they may be far more glittery than previously suspected. Whether you're willing to give up a quarter of your year's earnings on a diamond ring for your future spouse is ultimately up to you, though it seems you might not need to dig so deep after it was discovered that diamonds aren't quite as rare as we initially thought.