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%).
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.