Related Clues:

• It may pan out
• Miner's bonanza
• Coal source
• Galena or mispickel
• Hematite, e.g.
• German preposition
• Vein contents, perhaps
• Bauxite or galena
• Iron, for one
• Galena or cinnabar, e.g.
• Refinery supply
• Something to slag
• Aluminum source
• Mineral source
• Copper, for one