Related Clues:

• Magnesium source
• Grains used by pretzel makers
• Miner's discovery, perhaps
• Shaker's contents, sometimes
• It needs refining
• Margarita glass rim coater
• Klondike find, perhaps
• Shaker contents, perhaps
• Mineral bearing rock
• Get a lode of it
• Snow melter
• Underground treasure
• Table staple
• It's found in seams
• Galena, for instance