the girl's best friend, buried 100 miles deep

You may have already seen the revolutionary news that scientists have discovered an unimaginably huge trove of diamonds hiding deep, deep inside the earth—about 100 miles deep, as it turns out: about £150,000,000,000,000,000,000,000,000 (150 septillion pounds') worth.

Don’t tell the Hatton Garden gang: scientists just unearthed an eye-watering hoard of diamonds, so valuable it would completely destroy the world’s economy. The scientists reckon there’s a quadrillion tonnes of diamond buried in the ‘cratonic roots’ in continents. There’s just one, tiny, catch: the treasure trove is buried 100 miles down, deeper than any drill has ever penetrated, according to MIT researchers.

Cratonic roots are the most ancient sections of rock under tectonic states, shaped like upside-down mountains. The researchers estimate that the roots may have 1-2% diamond, meaning that about a quadrillion tons of diamond are buried there.

Given that a ton of diamond is 50,000,000 carats, worth at least £3,000 each, that comes out at a tasty £150,000,000,000,000,000,000,000,000 by our relatively unscientific calculations. ‘This shows that diamond is not perhaps this exotic mineral, but on the [geological] scale of things, it’s relatively common,’ says Ulrich Faul, a research scientist in MIT’s Department of Earth, Atmospheric, and Planetary Sciences.

‘We can’t get at them, but still, there is much more diamond there than we have ever thought before.’ The researchers concluded that there were diamonds down there due to an anomaly in seismic data – where sound waves seemed to speed up. Faul and his colleagues calculated that the anomaly could be caused by 1%-2% of diamonds in the ‘cratonic roots.’ Faul said, ‘Diamond in many ways is special. One of its special properties is, the sound velocity in diamond is more than twice as fast as in the dominant mineral in upper mantle rocks, olivine.’

Bringing up even a small portion of that deposit would indeed wreck the world's economy: with supply now suddenly outstripping demand, a diamond would become a common rock. Any drilling company that wanted to be first to get these diamonds (which seem to be only theoretical at this point) would need to hoard them and dole them out stingily, constricting supply and maintaining demand.

Otherwise, the idea that the earth has that much diamond is pretty astonishing.