A field or generic term for natural hydrous iron oxides, the most common phase being the mineral goethite, α-FeO(OH). Limonite occurs as a low-temperature mixture of phases and includes the so-called bog iron ores. It is the characteristic brown stain which coats rocks containing sulfide ores, such as pyrite and pyrrhotite, in the zone of weathering of these ores referred to as a gossan. A vast list of pseudonyms, such as limnite, hypoxanthite, and xanthosiderite, plague the earlier literature. Limonite is most commonly a mixture of greater or lesser fractions of goethite, hematite, ferric oxyhydroxide colloids, clays, and manganese oxides. It is formed by biogenic or inorganic precipitation in bog, spring, lacustrine, or marine deposits.