What is obsidian made of?

Related questions

1. Is Obsidian found in Pennsylvania?
2. Does Obsidian need to be cleansed?
3. Is Obsidian a precious stone?
4. Can you sharpen Obsidian?
5. Is Blue Obsidian natural?
6. How can you tell the difference between Onyx and Obsidian?
7. How do you shape obsidian?
8. What can you make with Obsidian?
9. Is Obsidian the same as Apache tears?
10. Is green obsidian natural?

Tags

1. #harder
2. #rhyolite
3. #volcanoes
4. #rapid
5. #obsidian
6. #percent
7. #igneous
8. #formed
9. #slightly
10. #lustre
11. #glassy
12. #about
13. #composition
14. #occurring
15. #water
16. #glass
17. #chemical
18. #viscous
19. #extremely
20. #window
21. #cooling
22. #natural
23. #similar
24. #silica