Related Clues:

• Raw metal
• Contents of a lode-bearing wall?
• Source of gold
• Valuable deposit
• Rock hound's find, perhaps
• Old furnace fuel
• Tram contents
• Underground asset
• Discovery in a seam
• Frosty's eye
• Anthracite, e.g.
• Smeltery material
• Nickel source
• Mineral bearing rock
• Smelting need