Across
- 2. rock formed by heat and pressure below Earth's crust
- 5. beautiful, rare precious stones
- 7. rock that forms when layers of sediment and organic material harden
- 11. scale used to determine hardness
- 12. rock like substance formed from decayed plant matter
- 15. rock formed from magma or volcanic lava
- 17. the way a mineral reflects light
- 18. a type of igneous rock
- 20. layer containing most of the Earth's mass
- 21. thin outer layer of the Earth
Down
- 1. type of sedimentary rock
- 3. hard natural substance made of one or more minerals that contain organic materials
- 4. the ability of a mineral to resist scratching
- 5. studies structure, rocks and minerals of the Earth
- 6. movement of sediment from one place to another
- 7. type of metamorphic rock
- 8. substance made of things that were never alive
- 9. where minerals are usually found
- 10. small bits of weathered rocks
- 11. inorganic substance found naturally in the Earth
- 13. how most sedimentary rocks were formed
- 14. center of the Earth
- 16. loose material on the surface of the Earth where plants grow
- 19. color of the mark when a mineral is rubbed on a harder surface