'When this cools quickly after an eruption, it can form a type of glass called obsidian'
lava
4-LETTER WORDS: When this cools quickly after an eruption, it can form a type of glass called obsidian
When this cools quickly after an eruption, it can form a type of glass called obsidian
When this cools quickly after an eruption, it can form a type of glass called obsidian
4-LETTER WORDS
lava
4-LETTER WORDS