Related Clues:

• Smeltery material
• Nickel source
• Mineral bearing rock
• Smelting need
• See 112-Down
• It's refined
• Mineral deposit
• Refinery rocks
• Prospector's discovery
• Forty-niner's find
• I-5 state
• Tram cargo, perhaps
• Extraction candidate
• Underground-railroad cargo
• Mine content