Diamonds from hell: A quadrillion tonnes of precious gems found inside the Earth

The Earth - full of diamonds.
The Earth - full of diamonds. Photo credit: Getty

Scientists have discovered a quadrillion tonnes of diamonds, and the good news is they're right here on Earth.

Or perhaps more accurately, in the Earth - and that's the catch. No one can reach them.

Researchers in US came across the huge stash whilst investigating an anomaly in seismic data. Sound waves that travelled through the Earth following quakes and tsunamis speed up when passing through parts of the Earth just beneath the crust.

"The velocities that are measured are faster than what we think we can reproduce with reasonable assumptions about what is there," said Ulrich Faul, MIT research scientist.

"Then we have to say, 'There is a problem.' That's how this project started."

Crunching the numbers led them to a sparkling discovery - between 1 and 2 percent of the rock beneath the Earth's tectonic plates is pure diamond.

"This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it's relatively common," said Mr Faul.

Much, much more - 1,000,000,000,000,000 tonnes, if you write it out as numerals. That's equivalent to the weight of 3 trillion Boeing 747s.

Diamonds' value comes about partly because of their scarcity, but don't expect engagement rings to get any cheaper right away - the closest are about 140km away.

"We can't get at them, but still, there is much more diamond there than we have ever thought before."

The deepest hole in the world ever drilled went down only 12.2km. It had to be stopped due to temperatures upwards of 180degC.

The researchers say the only way we'll get to the diamonds from hell would be if they're spewed up by a volcano.

The research was published in journal Geochemistry, Geophysics, Geosystems.