noun
- a dark volcanic glass formed by the rapid cooling of lava
Usage: geology
Examples
- The ancient people made sharp tools from obsidian.
- Obsidian forms when lava cools very quickly.
- The knife blade was crafted from black obsidian.
- Archaeologists found obsidian arrowheads at the site.
- The volcanic eruption created large deposits of obsidian.
- Native Americans traded obsidian across great distances.