Mineralogists from the University of Nevada, Las Vegas are reporting the surprising discovery of a new mineral. Called calcium silicate perovskite, traces of the mineral were discovered in a diamond formed deep in the earth’s mantle.
The mineral sample likely formed between 660 and 900 km below the planet’s surface. The mineral had previously been created in a laboratory setting, but it disintegrated when removed from the artificial high-pressure environment.
Researcher Oliver Tschauner and his colleagues were analyzing a diamond from Orapa, Botswana when they noticed flecks of the mineral. The scientists assigned the mineral the name “davemaoite,” after pioneering geologist Ho-Kwang “Dave” Mao. Diamonds serve as a direct window to the deepest regions of the mantle, because they do not morph as they rise closer to the surface. They do, however, scrape up microscopic “inclusions,” leading to the small presence of rare minerals in their composition.
Based on their assessments, the researchers estimate that davemaoite makes up five to seven percent of the lower mantle. Pockets of this uranium- and thorium-rich mineral could help explain why some parts of the mantle are hotter than others, expanding our understanding of deep earth. The researchers were pleasantly surprised by their findings. “The chances, we thought, of finding it were so low that we never really actively looked for it,” said Tschauner.
Source study: Science – Discovery of davemaoite, CaSiO3-perovskite, as a mineral from the lower mantle