Hematite is one of the most abundant minerals found on the earth's surface and in shallow crust. Hematite is a type of iron oxide with the chemical composition Fe2O3. This rock is a common rock-forming mineral that is often found in sedimentary, metamorphic and igneous rocks.
The mineral magnetite is iron oxide (Fe3O4), which is found in all three igneous, metamorphic and sedimentary rocks. This stone is often extracted from iron ore. Magnetite is also a mineral with the highest amount of iron (72.4%).