In case you weren’t already sure that diamonds aren’t as unique or valuable as advertisers want us to believe, the next blow to Big Diamond might have just arrived. Using sound waves, geologists have discovered a gigantic stash of the so-called precious stones deep in the Earth’s interior, possibly to the tune of a quadrillion tons.
The study began when an international team of researchers set out to solve a long-standing geological mystery. Scientists can infer what kinds of rock makes up different parts of the planet by studying seismic activity. Basically, the sound waves created as the result of earthquakes or volcanic rumblings will travel at different speeds through different types of rock, painting a picture of what’s down there.
But one area doesn’t behave like it would be expected to. Cratons are the oldest and most immovable slabs of rock on (or rather in) Earth, with roots stretching down from the center of the tectonic plates to a depth of up to 200 mi (320 km). The assumed makeup of these pillars would produce faster sound waves, but not to the speeds that have been observed.