Igneous Rocks

1. When lava cools above ground. this is called extrusive igneous rock.

1.1. Andesite

2. when magma cools underground. this is called intrusive igneous rock.

2.1. obsidian

3. grain size

4. mineral composition

5. coarse

6. fine

7. no grains

8. felsic

9. mafic

10. intermediate

11. ultramafic

12. lava/magma cools slowly

13. granite

14. lava/magma cools quickly

15. basalt

16. lava/magma cools really quickly

17. obsidian

18. high levels of silica leading to lighter color

19. granite

20. medium levels of silica leading to slightly darer color

21. granite

22. low levels of silica leading to dark color

23. basalt

24. there is pretty much no silica leading to very dark color

25. obsidian