Iron Ore | The Canadian Encyclopedia
Iron ore usually consists of iron oxides and carbonates. Its most important mineral forms are magnetite (Fe 3 O 4, 72.4% Fe), hematite (Fe 2 O 3, 69.9% Fe) and siderite (FeCO 3, 48.29% Fe). In Brazil, some ore that contains practically no other minerals can grade as high as 68% Fe, but the crude ore mined in Canada grades between 30 and 44% Fe.