Deep-Earth diamonds are revealing a trove of never-before-seen minerals

"Until Korolev peered at it a few years ago, no one had ever seen the mineral in nature. Normally, such deeply formed material doesn't survive its long journey up to the planet's surface. But this minuscule bit was trapped within a diamond, keeping its crystal structure intact. Powerful new lasers and x-rays are enabling geologists like Korolev to probe increasingly small flecks of minerals in deep diamonds."

"These tools have led to what one researcher calls an explosion of new mineral discoveries from Earth's mantle, the slowly creeping layer of rock that lies between the planet's crust and core. Discoveries in the past few years include breyite, grahampearsonite and goldschmidtite. Each new mineral adds a new piece to the puzzle of how rocks transform under heat and pressure within the planet."

"This in turn shapes estimates of the volume of elements, such as carbon and hydrogen, that are stored in the Earth's interior. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today."

"The crystal seen in Korolev's microscope is a case in point. Called bernwoodite, it's one of two new minerals Korolev and his adviser at the AMNH, Kate Kiseeva, and their colleagues recently discovered trapped in deeply formed diamonds. Both were just designated as new minerals by the International Mineralogical Association, though it has not yet officially announced bernwoodite's designation."

A mineral speck formed hundreds of kilometers beneath Earth can be observed when trapped inside a diamond, which preserves its crystal structure during the journey to the surface. New laser and X-ray methods let geologists probe smaller and smaller mineral inclusions in deep diamonds. These capabilities have produced many newly identified minerals from Earth’s mantle, including breyite, grahampearsonite, and goldschmidtite. Each discovery provides information about how rocks change under heat and pressure inside the planet. That knowledge helps refine estimates of how much of elements such as carbon and hydrogen are stored in Earth’s interior. New minerals such as bernwoodite have been found in deep diamonds and are being processed for official recognition.

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