1. Physical Geology Chapter 5

2. Big Definition! Mineral – a natural, usually inorganic solid that shows –Characteristic chemical composition –Orderly internal structure –Recognizable physical properties

4. Kinds of Minerals Silicates – has some combination of silicon (Si) and oxygen (O) and comprise 96% of the earth’s crust Non-silicates – no SiO compounds; 4% of the earth’s crust

5. Silicate Minerals Quartz – only Si and O Feldspar – most common silicate Ferromagnesians – iron and magnesium bearing compounds –olivine –Pyroxene –Amphibole –biotite

6. Non-Silicate Minerals

7. And Native Elements

8. All minerals in Earth’s crust have a crystalline structure of some kind. That is its “regular orderly structure”

9. What is a crystal? A solid whose atoms, ions, or molecules are arranged in a regular, repeating pattern

10. Diamond X-rays are used to study crystals X-rays pass through a crystal and strike a photographic plate producing an image of the atom/molecule arrangement

11. Silicate building block – the silicon/oxygen tetrahedron

12. Silicate Mineral Arrangements

13. Isolated do not link to other O or Si Rings link by sharing O Single chains share O (open rings) Double chains are bonded single chains Sheets share 3 O with others; 4 th with Al or Mg, which holds sheets Frameworks bond each tetrahedron to 4 others; and on and on…………..

14. Non-silicate arrangement Vast variety of crystalline structures May have tetrahedra similar to silicates but with different elements at center Minerals with same ion at center share properties, thus creating subgroups

15. How do we identify minerals? By physical properties such as –Color –Streak –Luster –Cleavage and fracture –Hardness –Crystal shape –density

16. Or by special properties such as –Fluorescence –Phosphorescence –Chatoyancy –Asterism –Magnetism –Radioactivity –Double refraction

17. Color Many typical colors, but additions of elements can cause changes; e.g., quartz vs. Amethyst Click here for more information

18. Streak Click here for more information

19. Luster Click here for more information

20. Cleavage and fracture Click here for more information

21. Hardness Click here for more information

22. Crystal shape Click here for more information

23. Specific gravity Click here for more information

24. Special properties Click here for more information