Under the continental plates are 1000 trillion tons of diamonds

A new study suggests that 120 to 150 kilometers (75 to 93 miles) under the Earth’s surface there is 1000 trillion tons of diamonds. The diamonds are in the “roots” of cratons, which are large sections of rock. Cratons lie beneath most continental tectonic plates.

They created a three-dimensional model of the velocities of seismic waves that traveled through the planet’s major cratons.

Vibrations from earthquakes and tsunamis tend to speed up when passing through cratonic roots. The speedup was greater than would be expected from the fact that cratons tend to be colder and less dense than surrounding structures.

The best explanation for the speeds actually observed underground was that 1 to 2% of the roots of the cratons was made up of diamonds, while the rest was made up of peridotite (the main type of rock in Earth’s upper mantle) and a little bit of eclogite rocks (from the ocean’s crust).

Journal Geochemistry, Geophysics, Geosystems – Multidisciplinary Constraints on the Abundance of Diamond and Eclogite in the Cratonic Lithosphere

Some seismic models derived from tomographic studies indicate elevated shear‐wave velocities (over 4.7 km/s) around 120–150 km depth in cratonic lithospheric mantle. These velocities are higher than those of cratonic peridotites, even assuming a cold cratonic geotherm (i.e., 35 mW/m2 surface heat flux) and accounting for compositional heterogeneity in cratonic peridotite xenoliths and the effects of anelasticity. We reviewed various geophysical and petrologic constraints on the nature of cratonic roots (seismic velocities, lithology/mineralogy, electrical conductivity, and gravity) and explored a range of permissible rock and mineral assemblages that can explain the high seismic velocities. These constraints suggest that diamond and eclogite are the most likely high‐Vs candidates to explain the observed velocities, but matching the high shear‐wave velocities requires either a large proportion of eclogite (over 50 vol.%) or the presence of up to 3 vol.% diamond, with the exact values depending on peridotite and eclogite compositions and the geotherm. Both of these estimates are higher than predicted by observations made on natural samples from kimberlites. However, a combination of less than 20 vol.% eclogite and ~2 vol.% diamond may account for high shear‐wave velocities, in proportions consistent with multiple geophysical observables, data from natural samples, and within mass balance constraints for global carbon. Our results further show that cratonic thermal structure need not be significantly cooler than determined from xenolith thermobarometry.

39 thoughts on “Under the continental plates are 1000 trillion tons of diamonds”

  1. There is allegedly enough gold to pave the Earth’s surface a meter in thickness. It;s also just as available as the diamonds are. The difference is that additive manufacturing will likely allow growing any size and shape diamond for future application when needed. As for more gold, the space rocks are a possibility.

  2. Diamonds have wider uses than jewelry- abrasives, heat conductors and durable coatings, just to name a few. Cheap diamonds would revolutionize industry. But the real challenge is in finding better ways of making them synthetically. The technique hasn’t changed since the 60’s. Basically it involves heating and squeezing the graphite to simulate mantle conditions. Then wait for weeks or months for the transformation. (A trace amount of iron makes the diamonds yellow, but harder.) Occasionally one of these old vises pop. They require great caution to ensure nobody is around when that happens. I understand lasers are also used, but not for industrial quantities. Really? That’s the best we can do? I’ve often wondered if we could accomplish the same thing going in the other direction. Instead of heating the graphite to near molten temperatures, why can’t we supercool it, and then squeeze. Electron configurations apparently become more flexible near absolute zero (hence, superconductivity). The 3 to 4 bond conversion of graphite to diamond just might proceed more smoothly. As crazy as this sounds, I refuse to believe there isn’t a better way. Harvesting select meteors? Who knows? We need to get more creative.

  3. Yep. Earth’s megalopolis and their transportation needs, besides of the many places in the Solar System where you need to live underground are much bigger treasures (and comparatively less risky).

  4. The speculation that there are diamond formations in the mantle has been around for many years. This just adds craton roots as another possible location. Basically, below a certain depth, the pressure is high enough that diamond becomes the most stable form of carbon. At lower pressures, graphite is the most stable. So this just says that craton roots are under higher pressure (and/or colder) than previously thought, or that diamonds migrate there from the mantle for some reason. This isn’t very significant beyond scientific curiosity. I don’t think it alters our understanding of Earth all that much, and it has zero technological or economical implications. We can’t access any of these diamonds, and even if we could, their technological usefulness is questionable. As for jewelry, there are more than enough diamonds in accessible deposits. The price is kept artificially high by monopolies.

  5. Actually, the value of diamond is artificially pumped through a very systematic establishment of cartels and oligopolies. It’s just carbon…. If the Boring company would pursue diamond mining, they would be quickly eliminated.

  6. There is allegedly enough gold to pave the Earth’s surface a meter in thickness. It;s also just as available as the diamonds are. The difference is that additive manufacturing will likely allow growing any size and shape diamond for future application when needed. As for more gold the space rocks are a possibility.

  7. Diamonds have wider uses than jewelry- abrasives heat conductors and durable coatings just to name a few. Cheap diamonds would revolutionize industry. But the real challenge is in finding better ways of making them synthetically. The technique hasn’t changed since the 60’s. Basically it involves heating and squeezing the graphite to simulate mantle conditions. Then wait for weeks or months for the transformation. (A trace amount of iron makes the diamonds yellow but harder.) Occasionally one of these old vises pop. They require great caution to ensure nobody is around when that happens. I understand lasers are also used but not for industrial quantities.Really? That’s the best we can do? I’ve often wondered if we could accomplish the same thing going in the other direction. Instead of heating the graphite to near molten temperatures why can’t we supercool it and then squeeze. Electron configurations apparently become more flexible near absolute zero (hence superconductivity). The 3 to 4 bond conversion of graphite to diamond just might proceed more smoothly. As crazy as this sounds I refuse to believe there isn’t a better way. Harvesting select meteors? Who knows? We need to get more creative.

  8. Yep. Earth’s megalopolis and their transportation needs besides of the many places in the Solar System where you need to live underground are much bigger treasures (and comparatively less risky).

  9. The speculation that there are diamond formations in the mantle has been around for many years. This just adds craton roots as another possible location. Basically below a certain depth the pressure is high enough that diamond becomes the most stable form of carbon. At lower pressures graphite is the most stable. So this just says that craton roots are under higher pressure (and/or colder) than previously thought or that diamonds migrate there from the mantle for some reason.This isn’t very significant beyond scientific curiosity. I don’t think it alters our understanding of Earth all that much and it has zero technological or economical implications. We can’t access any of these diamonds and even if we could their technological usefulness is questionable. As for jewelry there are more than enough diamonds in accessible deposits. The price is kept artificially high by monopolies.

  10. Actually the value of diamond is artificially pumped through a very systematic establishment of cartels and oligopolies. It’s just carbon….If the Boring company would pursue diamond mining they would be quickly eliminated.

  11. Reachable or not, I just love to hear the sound of the De Beers cartel gnashing its greedy collective teeth at even the remote possibility.

  12. A newer , albeit not much cheaper method is chemical vapor deposition(CVP). It is a slow method as it grows the diamond’s thickness one atomic layer at a time

  13. They might as well be in Jupiter’s core, in terms of economic impact here on Earth. Synthetic diamonds made here on the surface do have potential impact, though. I’ve heard this is a technology that has been delayed decades by the legal and not-so-legal tactics of diamond cartels.

  14. Reachable or not I just love to hear the sound of the De Beers cartel gnashing its greedy collective teeth at even the remote possibility.

  15. A newer albeit not much cheaper method is chemical vapor deposition(CVP). It is a slow method as it grows the diamond’s thickness one atomic layer at a time

  16. They might as well be in Jupiter’s core in terms of economic impact here on Earth. Synthetic diamonds made here on the surface do have potential impact though. I’ve heard this is a technology that has been delayed decades by the legal and not-so-legal tactics of diamond cartels.

  17. NBF – please use quadrillion instead of antique references like 1000 trillion. The readers of NBF can count that high. And other media outlets are using quadrillion already.

  18. NBF – please use quadrillion instead of antique references like 1,000 trillion. The readers of NBF can count that high. And other media outlets are using quadrillion already.

  19. NBF – please use quadrillion instead of antique references like 1,000 trillion. The readers of NBF can count that high. And other media outlets are using quadrillion already.

  20. Reachable or not, I just love to hear the sound of the De Beers cartel gnashing its greedy collective teeth at even the remote possibility.

  21. A newer , albeit not much cheaper method is chemical vapor deposition(CVP). It is a slow method as it grows the diamond’s thickness one atomic layer at a time

  22. They might as well be in Jupiter’s core, in terms of economic impact here on Earth.

    Synthetic diamonds made here on the surface do have potential impact, though. I’ve heard this is a technology that has been delayed decades by the legal and not-so-legal tactics of diamond cartels.

  23. There is allegedly enough gold to pave the Earth’s surface a meter in thickness. It;s also just as available as the diamonds are.
    The difference is that additive manufacturing will likely allow growing any size and shape diamond for future application when needed. As for more gold, the space rocks are a possibility.

  24. Diamonds have wider uses than jewelry- abrasives, heat conductors and durable coatings, just to name a few. Cheap diamonds would revolutionize industry. But the real challenge is in finding better ways of making them synthetically. The technique hasn’t changed since the 60’s. Basically it involves heating and squeezing the graphite to simulate mantle conditions. Then wait for weeks or months for the transformation. (A trace amount of iron makes the diamonds yellow, but harder.) Occasionally one of these old vises pop. They require great caution to ensure nobody is around when that happens. I understand lasers are also used, but not for industrial quantities.

    Really? That’s the best we can do? I’ve often wondered if we could accomplish the same thing going in the other direction. Instead of heating the graphite to near molten temperatures, why can’t we supercool it, and then squeeze. Electron configurations apparently become more flexible near absolute zero (hence, superconductivity). The 3 to 4 bond conversion of graphite to diamond just might proceed more smoothly. As crazy as this sounds, I refuse to believe there isn’t a better way. Harvesting select meteors? Who knows? We need to get more creative.

  25. Yep. Earth’s megalopolis and their transportation needs, besides of the many places in the Solar System where you need to live underground are much bigger treasures (and comparatively less risky).

  26. The speculation that there are diamond formations in the mantle has been around for many years. This just adds craton roots as another possible location. Basically, below a certain depth, the pressure is high enough that diamond becomes the most stable form of carbon. At lower pressures, graphite is the most stable. So this just says that craton roots are under higher pressure (and/or colder) than previously thought, or that diamonds migrate there from the mantle for some reason.

    This isn’t very significant beyond scientific curiosity. I don’t think it alters our understanding of Earth all that much, and it has zero technological or economical implications. We can’t access any of these diamonds, and even if we could, their technological usefulness is questionable. As for jewelry, there are more than enough diamonds in accessible deposits. The price is kept artificially high by monopolies.

  27. Actually, the value of diamond is artificially pumped through a very systematic establishment of cartels and oligopolies. It’s just carbon….

    If the Boring company would pursue diamond mining, they would be quickly eliminated.

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