Goethite is a hydrated iron oxide, Fe3+O(OH). Its hardness ranges from 5.0 to 5.5, and its specific gravity varies from 3.3 to 4.3. It forms needle-like crystals, and is not generally considered very interesting as a mineral specimen; its main use is as an iron ore. Colour brown.
Related to the mineral Feroxyhyte FeO(OH).
- List of minerals
- Iron oxides