Related Clues:

• Magnetite, for one
• Siderite, e.g.
• Mineral
• Steel factory input
• Mesabi yield
• Magnetic rock
• Smelted stuff
• Limonite, e.g.
• Mesabi Range wealth
• Siderite, for one
• Refined find
• Smelter's need
• Steelmaking need
• Steel foundry input
• Hematite, e.g.