Upon inspection of rock samples from the Vergenoeg fluorite mine in South Africa, they discovered that fayalite crystals in the sediment of granite-like magma could contain large amounts of heavy rare earth elements. The mineral, which is reddish brown to black in color, is mined mainly for use as a gemstone and is also used for sandblasting. Fayalite is found worldwide in igneous rocks and abyssal rocks.
Fayalite crystals in the sediment of granite-like magma can contain large amounts of heavy rare earth elements
“Atomic probe tomography maps confirm the integration of the HREEs into the fayalite crystal lattice, facilitated by lithium acting as a main charge balancing agent and by high REE content in the highly fractionated felsic parent melt associated with the Bushveld LIP [large igneous province], ”Reads the article. “The high HREE concentrations of fayalite in conjunction with its high modal abundance (> 95 vol%) indicate that the fayalite cumulations are the most important host for the HREE mineralization of the Vergenoeg precipitate.
To reach this conclusion, the scientists used laser ablation-inductively coupled plasma mass spectrometry analysis and noted that cumulative fayalite in the Paleoproterozoic Satisfied F-Fe REE precipitate of the Bushveld LIP contains the highest heavy REE content containing never recorded for the mineral olivine, with HREE enrichment of as much as 6000 × chondritic values.
“As heavy rare earth elements become increasingly scarce in the world market, the discovery of fayalite as a new potential source for detecting new deposits of rare earth is extremely important for the economy,” said Reiner Klemd, one of the study’s authors. , said. said in a media statement.
At present, the most well-known and economically viable sources of rare earths are in China, where more than 80% of them are refined. This has led to an almost monopolistic situation, with the Asian giant dominating international trade, especially in heavily scarce land.