Limonite and Hematite are two types of iron ore. Limonite is a hydrated iron oxide mineral, while Hematite is an anhydrous iron oxide mineral. Both are important sources of iron and are used in the production of steel. Limonite is usually found in sedimentary rocks, while Hematite is found in igneous and metamorphic rocks. Both minerals are mined for their iron content and are used in a variety of industries.