2. 3 Kinds of Rock Igneous – rock that has melted and re- solidified. Sedimentary – Formed from sediments that have been compacted and cemented together. Metamorphic – Rock that has been changed by heat and pressures.

4. Layers of the Earth

5. Some revision on mixtures, compounds and elements An element has one kind of atom A compound has two more kinds of atoms in a fixture ratio A mixture is mix of two or more substances that are NOT bonded.

6. Most common Elements in the Earth’s crust OXYGEN-46.4% SILICON-28.2% ALUMINUM-8.2% IRON-5.6% CALCIUM-4.2% SODIUM-2.4% MAGNESIUM-2.3% POTASSIUM-2%

7. Make up of the Earth’s Crust

8. How do Rocks differ from minerals? A mineral has a known chemical composition with a fixed ratio of elements. (could be an element or compound) Rocks are made up of two or more minerals. Therefore a Rock is a solid mixture of minerals the way cake is a mixture of eggs, flour, water etc.

9. How to identify Minerals Look at the following slides. Each shows several differ same samples of the same mineral. What feature might be most useful for identification. What problems might you encounter.

10. Examples of minerals Quartz

11. Sulphur

12. Hematite

13. Feldspar

14. Mica

15. Olivine

16. Some examples of rocks The following are some examples of different types of rocks.

17. Granite

18. Basalt

19. Most common minerals On the surface of continental crust: Quartz In the whole crust: Feldspar In the mantle: Olivine