Related Clues:

• Hopper fill
• This really smelts!
• A miner discovery?
• Metal from a mine
• Seam discovery
• Gold digger's quest?
• Anthracite or lignite
• Vein product
• Source of valuable matter
• A miner concern
• Rock that's mined
• Metalliferous rock
• Assayer's raw material
• Frosty's eyes
• Certain fossil fuel