Definition: Fermorite is a mineral that is composed of iron oxide and has a grayish-white to brown color, with a hardness of 3-4 on the Mohs scale. It is often found in the crust of the Earth's mantle and is responsible for shaping the planet's surface. The term "fermorite" was coined by John F. Fermentor, a British mineralogist, who described it as a rare mineral that is only found in the Earth's outermost layers