Hematite is the most important iron ore, as it contains about 70% of iron and is widely distributed around the world. It also has a high iron content and low impurities, making it a high-grade ore for steel production.
Magnetite is another major iron ore, as it contains about 72% of iron and is often found in association with hematite. It also has a high magnetic susceptibility, which makes it useful for beneficiation and extraction processes.
Goethite is a common iron ore, as it contains about 63% of iron and is often formed from the weathering of other iron-bearing minerals. It also has a brownish color and a fibrous or earthy texture, which gives it the name brown iron ore or limonite.
Limonite is a generic term for a mixture of hydrated iron oxides, usually containing about 59% of iron and varying in color from yellow to brown. It is often derived from goethite, lepidocrocite, or siderite, and is a common iron ore in tropical and subtropical regions.
Siderite is an iron carbonate, containing about 48% of iron and having a pale yellow to brown color. It is often found in sedimentary rocks, especially in coal beds and black shales, and can also form from the alteration of other iron minerals.