👉 Eichwaldite is a mineral with the chemical formula CaO. It is a type of quartz that forms crystals in the Earth's crust and can be found in various geological formations around the world, including those on the Moon and Mars. The name "eichwaldite" comes from its resemblance to the letter E (the capital of Germany). In the context of mineralogy, it is often used as a term for any quartz crystal that has been oxidized by exposure to air.
