(ORDO NEWS) — An African diamond gave scientists a tiny grain of a mineral still unknown to science. This discovery allowed chemists and geologists to look deep into the Earth‘s past.
Perfectly polished diamonds look perfect, but no stone is truly perfect. Inside even the most transparent diamonds, tiny inclusions of other chemical elements can be found.
For a jeweler, each such “grain” means a decrease in the cost of a stone, but for scientists, this is a real treasure.
Researchers in Canada have been lucky enough to discover something previously unknown to science: a mysterious mineral with very unusual chemical characteristics. It was hidden inside a diamond found in South Africa.
Only one grain of this strange mineral, the so-called goldschmidtite, has been found. The total size of the inclusions inside the diamond was only 100 micrometers (approximately the width of a human hair).
But, despite its modest size, the discovery gave science a unique opportunity to look into the past and study the ancient chemical reactions that took place in the depths of our planet.
“Goldschmidtite has a high concentration of niobium, potassium and the rare earth elements lanthanum and cerium, while the rest of the mantle is dominated by other elements such as magnesium and iron,” explains University of Alberta student Nicole Meyer.
“In order for potassium and niobium to make up the bulk of this mineral, it must have been produced by exceptional processes that concentrated these unusual elements,” he assures.
Geothermobarometric analysis estimates that the tiny dark green sample formed about 170 kilometers below the surface.
The mineral, formally known as (K, REE, Sr) (Nb, Cr) O3, is chemically similar to an artificial crystal with a perovskite structure called potassium niobate (KNbO3), but is only the fifth known natural perovskite group mineral ever seen in the Earth’s mantle.
It was named after the Norwegian geochemist Viktor Moritz Goldschmidt (1888–1947), who pioneered perovskite mineralogy. The sample was obtained from the Koffiefontein kimberlite pipe in the Kaapvaal craton in South Africa.
By the way, the Kaapvaal craton has repeatedly gifted researchers with some of the oldest rocks on the planet, providing scientists with fertile ground for all kinds of “mineral” discoveries.
Diamonds are a kind of “time capsule” capable of preserving minerals and individual inclusions for billions of years due to their amazing structure.
Perhaps in the future they will more than once become a source of valuable information, which humanity is simply not capable of obtaining by other means.
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