Davemaoite

Davemaoite is a high-pressure calcium silicate perovskite (${\displaystyle {\ce {CaSiO3}}}$) mineral with a distinctive cubic crystal structure. It is named after geophysicist Ho-kwang (Dave) Mao, who first described it from theory.

It is one of three main minerals in Earth’s lower mantle, making up around 5–7% of the material there. Significantly, davemaoite can host uranium and thorium, radioactive isotopes which produce heat through radioactive decay and contribute greatly to heating within this region[1] giving the material a major role in how heat flows deep below the earth's surface.[1]

Davemaoite has been artificially synthesized in the laboratory, but was thought to be too extreme to exist in the Earth's crust. Then in 2021, the mineral was discovered as specks within a diamond that formed between 660 and 900 km beneath the Earth's surface, within the mantle. The diamond had been extracted from the Orapa diamond mine in Botswana.[1] The discovery was made by focusing a high-energy beam of X-rays on precise spots within the diamond using a technique known as synchrotron X-ray diffraction.[2][3][4]

Calcium silicate is found in other forms, such as wollastonite in the crust and breyite in the middle and lower regions of the mantle. However, this version can exist only at very high pressure of around 200,000 times that found at Earth’s surface.