Which iron minerals are major sources of iron ore?

In the context of metallurgy and mineral processing, the most significant iron-bearing minerals used as sources of iron ore are oxides, carbonates, and hydrated oxides. The primary minerals include:

• Hematite (Fe₂O₃): This is the most important iron ore due to its high iron content (approximately 70 percent) and widespread abundance.12
• Magnetite (Fe₃O₄): A black, strongly magnetic mineral that serves as a major source of iron.32
• Limonite (hydrated ferric oxide hydroxide, FeO(OH)·nH₂O): Often associated with goethite, this brown-colored ore is a key component of lateritic deposits.435
• Siderite (FeCO₃): An iron carbonate mineral that, while containing a lower percentage of iron than the oxides, is a widespread and recognized iron ore.652

Hematite and magnetite are considered the most common and commercially significant types of iron ore. The quality of these ores is determined not only by their iron content but also by the presence of gangue—impurities such as silica and phosphorus that must be managed during the smelting and steelmaking processes.27