The correct answer is - (1) hematite.
The hematite represents a mineral form of iron oxide (one of the several). It varies in color from black to steel, silver gray or brown to niances of reddish brown. Hematite is the oldest known iron oxide mineral to have formed on Earth. This iron oxide is harder than the iron itself, but is it more britalle on the other hand. It is the main iron ore that is mined throughout the world. Hematite forms a complete solid solution at temperatures that are above 950 C degrees.
