Researchers Discover A Quadrillion Tons of Diamonds in Earth’s Deep Crust

By Nathaniel Scharping | July 16, 2018 4:40 pm
(Credit: RTImages/Shutterstock)

(Credit: RTImages/Shutterstock)

Earth’s interior is dark, but filled with diamonds.

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. Parts of Earth’s mantle may be up to two percent diamond by composition, far more than previously suspected. In terms of sheer mass, that works out to around a quadrillion, or thousand trillion, tons of diamond.

Sparkly Science

A team led by a researcher from the University of California, Santa Barbara looked at the way seismic waves travel through Earth’s depths, and found that they were moving faster than expected. Analyzing seismic waves is a fairly standard way of determining the composition of our planet’s interior, for the simple reason that they’re one of the few things that we can detect actually traveling through it. Vibrations from earthquakes don’t just travel along the surface, they move down through the body of our planet as well — and a network of seismographs around the world is listening in to every shake and shudder our planet makes.

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. The latest insights come thanks to years of seismic data from the USGS, used to solve a persistent mystery among geologists. When the seismic waves travel through the cores of tectonic plates — known as cratons, and looking something like inverted mountains — they move faster than they should based on current models of their composition.

Because we can’t just go look at the 100-miles-deep cratons ourselves (the deepest hole we’ve ever dug didn’t even get a tenth of the way), the researchers built a virtual mantle using a computer algorithm and played around with different compositions until they found one that matched up with what they were observing.

The best fit, they say in a paper published in the journal Geochemistry, Geophysics, Geosystems, was made up largely of the minerals peridotite and eclogite, with a healthy sprinkling of diamond. This combination would make cratons less dense than previously thought, which would explain why the seismic waves travel faster than older models called for. The diamonds, though present at a relatively low concentration, help to stabilize the cratons, the researchers say, and also pass on vibrations extremely quickly.

The deep parts of cratons, known as the roots, are also near where diamonds form in the first place, in the blazing heat and crushing pressures found deep inside the planet. Down there, diamonds may not be so rare after all — it’s just difficult for them to make it to the surface and onto the rings and earrings of human beings.

MORE ABOUT: earth science
  • Uncle Al

    Don’t drill, excavate! Concrete repurposes astounding volumes of aggregate. Blast and haul 50 vertical feet/day, 24/7 running three shifts, mandatory “unemployed” labor. 3.4 miles depth/year. In 30 years we’ll all be wearing diamonds on the soles of our shoes.

    If loud noises are bothersome, gene-gineer rock weevils to unbuild the worlds’ first dimaryp, Think of the tourism!

  • Jamie-lee Newcombe

    They’re in the planet for a reason! Stop being money hungry, diamond obsessed, narcissistic, small-minded people- who keep taking from our planet finite resources, that would almost undoubtedly serve a purpose – or why would they be there?!


    Leave nature alone, and thriving for your descendants for once and stop being so selfish, greedy, and just plain stupid about the decisions you make.
    And start taking reasonable and caring decisions for every species, and all of nature – it created you. And you take, take, take until there’s nothing left.

    Don’t cry when the planet starts changing again because of your selfish, unreasonable, unrealistic decisions.

    Grow up. I’ve come to realise that you guys at the top of all these decisions and actions, are inconsiderate and greedy, power hungry and down right inhumane.

    Try and tell me I’m wrong – everyone with half a brain knows how wrong it is. Ask them, instead of speaking for us. I’m so over it – because I actually have respect for my origins, the things that sustain me – that grow in the dirt, provided by the planet, the resources inside it that keep it working properly etc

    Continually taking parts from the Earth is literally akin to taking organs and vital fluids out of a human body and expecting it to still function properly.
    Enlighten me, were is the logic, rationality, and compassion in these kinds of human endeavours?


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!


See More

Collapse bottom bar