Related Clues:

• Metal-bearing minerals
• Underground sources of income
• Valuable vein
• Smeltery needs
• Raw metal
• Contents of a lode-bearing wall?
• Source of gold
• Mineral sources
• Valuable deposit
• Rock hound's find, perhaps
• Tram loads, often
• Prospectors' prizes
• Tram contents
• Bauxite and galena
• Underground asset