Two diamonds discovered in South Africa are forcing scientists to rethink how the deep interior of the Earth works. They analyzed them, and they discovered that the coexistence of opposite chemical microenvironments in the middle of the mantle could be possible, hundreds of kilometers beneath the surface.
The finding was published in the journal Nature, and it not only provides clues about how diamonds form, it also helps to understand a complex geological processes that directly impact phenomena like volcanism or large-scale carbon circulation. That’s incredible, don’t you think?
Hidden inside the Earth
These diamonds were extracted from the Voorspoed mine. But they are not valuable only because their appearance, listen, they act as time capsules, inside, they preserve intact chemical traces from their formation, between 280 and 470 kilometers deep!
And wait, because they show signs of two opposite redox environments, one oxidizing and one reducing, coexisting in the same place, that was impossible (until now, of course). Reduced metals and carbonated minerals should be at opposite, incompatible extremes, but these stones prove otherwise.
Flaws for jewelry, treasures for science
Those tiny fragments of minerals, gases or liquids get trapped when a diamond grows, in the jewelry market they called it “imperfections” but they are completely perfect for geologist, who are looking for evidences of what happens in the depths, where no probe can reach!
In this case, the inclusions showed radically different chemical signals from each other. The analyses revealed that the diamonds formed when carbonated minerals and reduced metals reacted in the same environment, creating the perfect conditions for crystallization. These chemical signals have remained intact for millions of years allowing scientists to observe that process.
A look into the heart of the planet
Earth’s interior is much more varied and dynamic than previously thought. It is not a homogeneous block but a mosaic of microenvironments with different chemistries coexisting at great depths.
Understanding these zones can help explain how certain special volcanoes originate (those that generate kimberlites, the rocks that transport diamonds to the surface), and how carbon moves inside the Earth.
The story behind the stones
The analyzed diamonds were donated by De Beers, the historic South African company. For more than a year, researchers did not know how to classify them: their chemical characteristics did not fit into any known pattern.
After multiple tests and spectroscopic analyses, they managed to decipher their composition. Their rarity is not in their shape or brilliance but in the internal chemistry that has remained intact since the moment they formed in the mantle.
Key questions!
- What exactly are inclusions? Microscopic remains of materials that were trapped when the diamond formed. Since the Earth’s depths remain stable for millions of years, these inclusions act as a chemical photograph of the past.
- Why is it important? Because it shows that opposite chemical environments can coexist in the mantle, something that current geological models did not consider.
- What implications does it have? It opens new ways to study the deep Earth and helps to understand how carbon is recycled, how continents evolve, and how some volcanoes manage to carry materials from the interior to the surface.
A new chapter for modern geology
These two diamonds do not only tell their own story. They are also helping tell the story of the entire planet. The coexistence of opposite chemical environments at great depths forces a rethink of established ideas about the structure and behavior of the mantle.
In the end, what these stones have done is remind us that the Earth still holds secrets that we can only decipher if we know how to look in the right places… even inside a diamond.