Solutions A dark volcanic rock has 5 entries with similar clues

• 4-letter words
• tuffRock formed from volcanic ash
• 5-letter words
• shaleA slatelike dark clay rock
• magmaGlassy volcanic rock
• 8-letter words
• obsidianA dark glasslike volcanic rock formed by rapid solidification of lava
• 9-letter words
• negativesPhotographic films on which light is dark and dark is light