Supercomputers Reveal Earth’s Incredible Secret Diamond Engine – by Darren Orf (Popular Mechanics – June 1, 2023)

The discovery has massive repercussions for humanity as we know it.

Diamonds primarily need three things to form: pressure, heat, and lots of time. Those three ingredients can be easily found in the Earth’s mantle—the goopy, extra hot geologic soup that separates the planet’s core from its crust. But if these precious stones form some 100 miles below the surface, how exactly do they show up in mines and jewelry stores across the globe?

For decades, scientists have known that volcanic eruptions of an igneous rock known as kimberlite can contain diamonds in their rock matrix, and such kimberlite hot spots can be found in South Africa, the northeastern U.S., and Siberia, among other places. So while this volcanic phenomena essentially burps up diamonds, what is the geologic engine behind those eruptions?

Researchers from the University of Wollongong Australia analyzed the past billion years of Earth’s geologic movement to understand the inner machinations of kimberlite in the Earth’s mantle.

The team discovered structures called “pillars of heat,”—stretching 2,900 kilometers (1800 miles) below the Earth’s surface and rooted right above the planet’s core—an idea first explored in the 1970s. The results were published last month in the journal Nature Geoscience.

For the rest of this article: