Scientists from the Massachusetts Institute of Technology ( MIT) and Penn State University (United States) have detected countless tons of diamonds located tens of kilometers deep in the Earth.
According to the authors of the project, the number of brilliant gems that hide in the upper portion of the mantle is much greater than previously thought, and rocks of all kinds, formed millions of years ago, are constantly affected by rigidity, temperature, density. and geological composition of the planet .
Naturally, diamonds form underground in cratons, ancient rock masses known as Archaeozoic cores, at meteorite impact sites, and through the eruption of deep-rooted volcanoes.
Beneath countless layers of rocks and geological materials, these glowing stones hide and form all sorts of coloring while harboring any sort of material within their crystalline structures. These gems, however, are invisible to the naked eye and require the use of sound waves to be identified.
Using seismic wave capture tools, the researchers gathered data from different models that simulate the three-dimensional noise of waves moving across the Earth. Considering composition, buoyancy and electromagnetism, they adjusted the exact speeds of the waves based on the materials they are formed from.
It was then that the results revealed the existence of about 1 quadrillion — 1 and 15 zeros — of tons of diamonds located in the layer of the Earth known as the “cold mantle” (which goes from 30 km to 2,9 thousand km deep).
According to the researchers, the glowing stones were considerably accelerating the seismic activity of the cratons, acting on about 2% of the roots, mixing with carbon dioxide and carbon-rich minerals such as graphite and calcite.
“This shows that diamond might not be this exotic mineral, because on the [geological] scale of things, it’s relatively common,” said MIT scientist Ulrich Faul, project leader. “We can’t reach them, but there are still a lot more diamonds there than we thought before,” he said.
A sea of blue diamonds
In 2018, geologist Evan Smith, from the North American Gemological Institute, announced that blue diamonds tend to be born below the concentration of crystals and can appear in regions up to 4 times larger, in the central portion of the Earth’s mantle. The difficulty of capturing them, then, would be one of the main factors to make the mineral more expensive in the jewelry market, consequently hindering access to scientific research.
So far, just under 50 diamonds have been analyzed, with their origins estimated at locations between 410 km and 660 km deep. However, other samples indicated properties of even lower levels of the planet, creating a mystery about what these stones could be encapsulating in deeper projections.
Currently, the hypothesis that is supported is that materials slide, via subduction and tectonic events, into the mantle and penetrate the surface layers of gemstones when they are incorporated into water-rich minerals, such as boron.
In the distant future, since humans have never been able to dig more than 12 kilometers deep into the Earth, will there be conditions to reach this impressive mineral wealth? Study author Joshua Garber, also a postdoctoral researcher at Penn State University, says it is unlikely on “human scales”, but does not rule out continuing studies to find out what the bottom of the planet hides .