IOI
For the first time, scientists have discovered a never-before-seen mineral in a diamond dug deep beneath the Earth’s surface. Calcium silicate perovskite is a mineral that forms as a result of the extreme pressure and temperature present in the deep mantle. Davemaoite is the name given to the mineral.
The mineral has a crystalline structure that is generated under high pressure and temperature circumstances found only deep below the Earth’s layer trapped between the core and the crust, and is named after geophysicist Ho-kwang (Dave) Mao for his investigations on high-pressure elements. Scientists have anticipated its presence for a long time, but just on the surface.
Calcium silicate perovskite, CaSiO3, is perhaps the most geochemically significant phase in the lower mantle, according to a study published in Science. It stores elements that are incompatible in the upper mantle.
The mineral included radioactive isotopes of uranium, thorium, and potassium, according to chemical examination. “Davemaoite may thus contain three of the key heat-producing elements impacting heat generation in Earth’s lower mantle,” according to the report. “Uranium and thorium were previously proved experimentally.”
Researchers led by Oliver Tschauner of the University of Nevada’s Department of Geoscience examined a greenish, octahedral-shaped diamond dug up from Botswana’s Orapa mine, which is the world’s largest opencast diamond mine. The diamond was subsequently sold to George Rossman, a mineralogist at the California Institute of Technology, and Tschauner began analysing it for a study of minerals trapped in deep-Earth diamonds, according to Nature.
“The discovery of davemaoite came as a surprise,” Tschauner told Live Science.
What makes this discovery so interesting?
The tendency of rare Earth minerals generated deep under the surface to lose molecular structure when exposed to ambient conditions is one of the most significant challenges in researching them. The latest finding of the mineral, however, has piqued the interest of scientists since it has maintained its structure despite being uncovered decades ago.
It was discovered contained inside a super-deep diamond, making it just the second high-pressure mantle silicate ever discovered on Earth’s surface. Yingwei Fei, a geophysicist at the Carnegie Institution for Science, writes in an editorial accompanying the discovery in Science, “No one has ever been able to extract a high-pressure calcium silicate from the lower mantle. This is because the high-pressure CaSiO3-perovskite is “unquenchable,” which means it loses its structure when it is removed from its high-pressure environment.”
The International Mineralogical Association’s Commission on New Minerals, Nomenclature has now recognised the mineral.
“The discovery of davemaoite inspires hope for finding other difficult high-pressure mineral phases in nature. Being able to obtain more direct samples from the inaccessible lower mantle would fill in our knowledge gap regarding the chemical composition and variability of our planet’s depths,” Fei said in a statement.
