Wüstite is a mineral composed primarily of iron oxide, specifically FeO. It typically forms in high-temperature environments, such as during the cooling of molten rock or in the reduction of iron ores. Wüstite is usually found in shades of black or gray and has a metallic luster. This mineral is significant in the study of geology and mineralogy because it can provide insights into the conditions under which it formed. Wüstite is also important in the production of iron and steel, as it can be a byproduct of the smelting process.