Related Clues:

• Obsidian, once
• Shade of gray
• Pinatubo product
• Silvery-gray
• Barbecue residue
• Etna outpouring
• Kilauea flow
• Slow roller
• Magma exposed
• It may be gone in a flick
• Wood used for tool handles
• Type of tree
• Molten spew
• Molten matter
• It may be volcanic