Related Clues:

• Unwrought iron
• Nugget holder
• Blast furnace material
• Buried treasure
• Driller's discovery
• Prospecting find
• Silver source
• Boxcar cargo, perhaps
• 50-Down member's find
• Lake Oswego st.
• Mined material
• Elementary stuff
• See 29 Down
• Shipment to a steel mill
• Cores core?