Both copper and iron belong to metals, and most metals in nature mainly exist in the form of compounds. The main component of magnetite is ferroferric oxide, and its chemical formula is: the main component of Fe3O4 magnetite is iron oxide, and its chemical formula is: the main components of Fe2O3 pyrite are: CuFeS2; The main component of malachite is basic copper carbonate, and its chemical formula is Cu 2 (OH) 2 CO 3.

So, the answer is: combined state; Ferroferric oxide; fe2o 3； ? CuFeS 2； Copper carbonate.