Why do rocks spark?

Related questions

1. What is the difference between chert and flint?
2. How do you get a bank in lumbridge cellar?
3. Is Flint water safe to drink now?
4. What are in thieves tools?
5. How do you identify Flint?
6. Is there a bank in lumbridge?
7. Can you get flint from breaking gravel with a torch?
8. How do you get Flint?
9. Can you boost to make infernal AXE?
10. What is Tinderbox Festival?

Tags

1. #actually
2. #because
3. #together
4. #common
5. #chips
6. #cause
7. #break
8. #wikipedia
9. #reason
10. #simply
11. #types
12. #results
13. #others
14. #struck
15. #softer
16. #flint
17. #start
18. #would
19. #rocks
20. #spark
21. #particles