Goethite (prounounced 'Ger-thite') is an iron bearing mineral similar to hemitite. It is usually the process of weathering that leads to the development of goethite, which appears as a rusty, microcrystaline coating on metal. This sample, however, is crystaline goethite, which exhibits radial needle-like crystals and a snaggly texture. The specimen is about an inch tall.