The mineral used in the production of steel and to give color to paint is Iron Oxide, also known as rust. Fe2O3. In its natural state, iron oxide is found as the mineral hematite, which is reddish-brown in color, or as the mineral magnetite, which is black in color. It also gives rust its orange/brown color.

In the production of steel, iron oxide is used as an oxidizing agent to remove impurities from the molten iron. During this process, oxygen combines with the impurities to form slag, which is then removed from the molten metal. Once the impurities have been removed, the metal can be cooled and rolled into steel sheets or other products.

Iron oxide is also used to give color to paint. Pigments made from iron oxide come in a variety of colors, including red, yellow, brown, and black. These pigments are made by heating iron oxide powder at high temperatures with various other chemicals. By carefully controlling the temperature and the reaction conditions, different colors can be achieved. These pigments are then used to add color to paints, coatings, ceramics, and other products.