limonite

Any of a group of widely occurring yellowish-brown to black iron oxide minerals, essentially FeO(OH)·nH₂O, used as a minor ore of iron.

An important iron ore which is found earthy, concretionary, or mammillary and fibrous.

Hydrous sesquioxide of iron, an important ore of iron, occurring in stalactitic, mammillary, or earthy forms, of a dark brown color, and yellowish brown powder. It includes bog iron. Also called brown hematite.

any of several natural hydrous iron oxides; often a mixture of goethite and hemite with clays and manganese oxide

a widely occurring iron oxide ore; a mixture of goethite and hematite and lepidocrocite