FeOOH A yellow-brown iron oxide mineral Goethite occurs in almost every soil type and climatic region, and is responsible for the yellowish-brown color in many soils and weathered materials
Widespread iron hydroxide mineral, -FeO(OH), the most common ingredient of iron rust. In terms of relative abundance, it is second only to hematite (-Fe2O3) among iron oxides. Goethite varies in colour from yellow-brown to red and is the source for the pigment known as yellow ocher; it is also the primary mineral in some important iron ores, such as those in the Alsace-Lorraine basin in France. Other important deposits are found in the southern Appalachian Mountains of the U.S., and in Brazil, South Africa, Russia, and Australia
A hydrous oxide of iron, occurring in prismatic crystals, also massive, with a fibrous, reniform, or stalactitic structure