Scientists Find A Completely Unknown Mineral Called 'Goldschmidtite' Buried Inside A Diamond

Diamonds may be widely coveted, but that might have more to do with an artificially created scarcity as opposed to actual looks.

They carry tiny flaws and blemishes called "inclusions", chemicals trapped in their veins. But sometimes, those flaws are remarkable.

A macro shot of a diamond with an inclusion - Wikimedia Commons

To the average jeweller, diamond inclusions might be something they wish could be removed so it would be worth more. To a scientist though, it could be a wealth of information, like this latest discovery.

Researchers from the University of Alberta in Canada have found something truly remarkable, a discovery the world has never seen before. They've uncovered a previously unknown mineral, embedded within a flaw in a diamond dug from the earth in South Africa.

Their discovery is actually pretty impressive. Because though the discovery is huge, the sample itself is incredibly tiny. The researchers found only a single grain of the new mineral embedded in the speck of diamond. In total it measures just about 100 micrometres across, about the width of a human hair.

The diamond speck, at a 100 nanometre magnification - Nicole Meyer/American Mineralogist/University of Alberta

They call it goldschmidtite.

Because of the mineral's previously unknown nature, as well as its unique chemical signature, scientists believe it could be invaluable towards unravelling the secrets of time buried deep within the Earth.

"Goldschmidtite has high concentrations of niobium, potassium, and the rare earth elements lanthanum and cerium, whereas the rest of the mantle is dominated by other elements, such as magnesium and iron," explains University of Alberta PhD student Nicole Meyer. "For potassium and niobium to constitute a major proportion of this mineral, it must have formed under exceptional processes that concentrated these unusual elements."

The Goldschmidtite grain at a 500 nm magnification- Nicole Meyer/American Mineralogist/University of Alberta

The tiny dark-green sample is estimated to have been formed about 170 km below the Earth's surface. Formulaically known as (K,REE,Sr)(Nb,Cr)O3, it's apparently chemically similar to an artificially engineered crystal called potassium niobate (KNbO3). It's been named in honour of the 19th-20th century Norwegian geochemist Victor Moritz Goldschmidt, who helped pioneer perovskite mineralogy. Perovskite is the name given to this particular structure of crystal.

The diamond was recovered from the Koffiefontein pipe in South Africa, a world-famous diamond production facility operated by industry giant De Beers. It's also home to some of the oldest rocks on the planet, so scientists are excited about piecing together the history that gave birth to this tiny grain of rock.