Hematite is iron oxide and one of the most abundant and ubiquitous minerals on the earth's surface. It is the source of the red coloration in 'painted deserts' and the red stain seen on rocks everywhere. Although the mineral often appears black, its powder (also known as 'streak') is bright red, a useful feature in identification. Hematite can be powdery, crystallized, banded or, as in the material from the iron ore deposits near Lake Superior, Michigan, lumpy and nodular, a type of aggregation known as botryoidal. Hematite is the most important ore of iron.