Hematite or haematite is the main ore of iron. It is mostly iron(III) oxide. Millions of tons are dug up every year to feed to blast furnaces to make steel. It is a mineral related to corundum and is an oxide.
It has a metallic luster. It has no cleavage (the way a mineral breaks) but does have a fracture. The fracture is irregular and uneven. Hematite on the hardness scale is 5 to 6. It has a bright red to dark red streak. To find the streak, you take the mineral and run it across a plate of unglazed porcelain. The colors vary from metallic gray to a dark, rough and earthy red color. Hematite has a chemical formula of Fe2O3.