Sources of iron can be found in a variety of ores, which are rocks or minerals from which a metal or valuable mineral can be extracted. Ores are typically mined from the earth and contain a variety of elements, including iron. Iron ore is one of the most abundant elements on Earth, making up about 5% of the Earth's crust. Iron ore is typically found in sedimentary rocks, such as hematite, magnetite, and limonite. Iron ore can also be found in igneous rocks, such as basalt and gabbro.