Related Clues:

• Valuable vein
• Raw metal
• Contents of a lode-bearing wall?
• Source of gold
• Mesabi output
• Valuable deposit
• Rock hound's find, perhaps
• Limonite, for one
• Tram contents
• Minnesota resource
• Underground asset
• Discovery in a seam
• Smeltery material
• Nickel source
• Mineral bearing rock