MIT Team Finds Gigantic Diamond Cache in the Earth’s Mantle

Diamond Reserves

Gigantic Diamond Cache

Diamonds take millions of years to form, and this leads many people into believing that they are exceptionally rare. De Beers has certainly helped that along by publicly stating in 2016 that we would run out of diamonds in 25 years, but this simply is not true. A new discovery confirms that the Earth holds plenty of diamond reserves under its surface.

MIT researchers have just found an underground deposit of diamonds weighing over a quadrillion tons. If you have not heard the term before, 1 quadrillion equals a thousand trillion, which is a lot. However, the new find certainly will not bring a diamond rush, mainly because these precious minerals are too deeply placed. In fact, at 90 to 150 miles under the surface, they are deeper than a drilling expedition has ever reached yet.

What this proves is that diamonds are not as exotic as we thought them to be, and are in fact common as things go. The latest discovery was made using seismic technology, which let the researchers analyze sound waves travelling through the Earth. Quite by accident, these scientists detected a huge concentration of diamond inside what are called cratonic roots. The latter get their name from essentially being inverted mountains that stretch down to the mantle. MIT’s official statement called them “the oldest and most immovable sections of rock that lie beneath the center of most continental tectonic plates.”

The project started off as a dig into why sound waves significantly sped up while passing through ancient craton roots. For this, the team got together virtual rocks made up of various mineral compositions, and checked the varying speeds at which sound travelled through them. Diamond is special in that sound moves through it over twice as fast as through olivine, which is the most commonly found mineral in upper mantle rocks. The speeds the team had originally noted indicated cratons containing at least one to two parts diamond in every hundred.

With this discovery, the new belief among scientists is that ancient underground rocks hold at least 1000 times as much diamond as previously expected. Advances in technology will hopefully allow us to someday reach and tap into these reserves. Until then, the discovery serves no other function than to tell us that diamonds are not as rare as most jewelers would like us to think.