Related Clues:

• Source of iron
• It may have a silver lining
• Tram filler
• It's fine for a refinery
• Pay dirt
• Miner's quest
• Lead ___
• Bauxite, e.g.
• Zoomed
• Hematite, for one
• Bauxite or magnetite
• It might be picked apart
• Smeltery supply
• Valuable find
• Underground deposit