A mineral found inside a diamond that reveals the Earth’s interior The tiny black specks can be obser ved in a diamond extracted in Orapa , a mine in Botswana . They are inclusions of a mineral found in Earth’s mantle, called davemaoite. In 2021, scientists found this mineral in nature for the first time (it had previously only been synthesised in laborator y experiments). Davemaoite is a calcium silicate containing radioactive uranium, thorium and potassium, which generate one third of the amount of heat in the Earth’s lower mantle. It therefore contributes to the circulation of heat between the mantle and the crust, which drives processes such as plate tectonics. The mineral cannot exist on the surface as it is only stable under conditions of high pressure and temperature, such as those found in the lower mantle, at depths greater than 660 km. But these particular specks were found inside a diamond that transported them intact from deep in the Earth . It is the structure of the diamond that keeps the inclusions at high pressure. Science News (Adapted) Rare mi neral s recently di scovered The strangest minerals on Earth Nevadaite, composed of vanadium and copper, is formed under ver y restricted conditions. Its cr ystals are microscopic. Only two specimens have been found: one in Nevada (USA) and one in Kyrgyzstan . It was approved by the International Mineralogical Association (IMA) in 2002. Ichnusaite is created through a subterranean mixture of two radioactive elements: thorium and lead . Only one specimen has ever been found: in Sardinia (Italy) in 2013. El País (Adapted) > Research what features a mineral must have to be considered rare. > The article in El País speaks of another mineral, fingerite, discovered in 1940. Describe its features. > Search the internet for images of the mineral davemaoite. Describe what you see in them. 6
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