Classroom presentations to accompany Understanding Earth , 3rd edition

1. Classroom presentations to accompany Understanding Earth, 3rd edition prepared by Peter Copeland and William Dupré University of Houston Chapter 2 Minerals: Building Blocks of Rocks

2. Minerals: Building Blocks of Rocks Breck P. Kent

3. A naturally occurring, inorganic solid with an ordered internal structure and a narrow range of chemical composition Mineral

4. Fig. 2.1

5. Rock A naturally occurring consolidated mixture of minerals or mineral-like substances

6. A rigid sphere about 1 angstrom (Å) in diameter -- an angstrom is 10-10 m At the center of an atom is a nucleus which contains most of the mass of the atom Protons with a positive charge Neutrons with no charge -- neutral Quarks and other interesting things Atoms

7. Electrons(E): negative charge, very little mass Protons(Z): positive charge, mass 1832 times greater than electron Neutrons(N): no electric charge, mass 1833 times greater than electron Atoms

8. Abundance of the elements (wt. %) Crust Whole Earth Oxygen 46.3 % 29.5% Silicon 28.2% 15.2% Aluminum 8.2% 1.1% Iron 5.6% 34.6% Calcium 4.1% 1.1% Sodium 2.4% 0.6% Potassium 2.1% 0.1% Magnesium 2.3% 12.7% Titanium 0.5% 0.1% Nickel trace 2.4% All others trace 2.7%

9. Electrons orbit around the nucleus in discrete shells. Atomic structure Nucleus: protons, neutrons

10. Fig. 2.2a

11. First level (K) 2 electrons Second level (L) 8 electrons Third level (M) 18 electrons Fourth level (N) 32 electrons Energy-level shell:the space occupied by electrons of a particular energy level

12. L K Fig. 2.2b

13. L K Fig. 2.2c

14. Fig. 2.3a

15. Fig. 2.3b

16. Fig. 2.3c

17. Chemical characteristics of elements determined largely by number of protons # of protons = atomic number (A) # of neutrons (N) + A = atomic weight (Z) Atomic structure

18. Ion An electrically charged particle composed of an atom that has either lost or gained electron(s) to or from another atom.

19. Ions When an atom loses or gains an electron it is called an ion. Positively charged ions (loss of electron) are called cations. Negatively charged ions (gain of electron) are called anions.

20. Important ions in minerals anions charge cations charge Si +4 K +1 Ca +2 Na +1 Al +3 Mg +2 Fe +2 or +3 O -2

21. Ionic Attraction Forms NaCl (Halite) Fig. 2.4c

22. Electron Sharing in Diamond Fig. 2.5

23. Oxygen O Magnesium Mg Silicon Si Iron Fe Aluminum Al Sodium Na Potassium K Calcium Ca Carbon C Titanium Ti Hydrogen H Argon Ar Uranium U Zirconium Zr Strontium Sr Lead Pb Chemical Symbols

24. Periodic Table of Elements Fig. 2.6

25. (H+) (Na+) P = Proton N = Neutron Fig. 2.7 (Mg2+)

26. (O2-) P = Proton N = Neutron (Cl-) Fig. 2.7

27. Carbon Tetrahedron of Diamond Fig. 2.8a

28. Network of Carbon Tetrahedra Fig. 2.8b

29. Atomic Structure of Sodium Chloride (Halite) Fig. 2.9

30. Ultrahigh Vacuum Scanning Tunneling Microscope Image of Galena Fig. 2.10 Kevin M. Rosso & Michael F. Hochella, Jr

31. Galena Fig. 2.10b Chip Clark

32. Perfect Crystals Halite (cube) Quartz (hexagonal) Fig. 2.11

33. Halite (Cubic) and Quartz (Hexagonal) Ed Degginger & Bruce Coleman Breck P. Kent

34. Quartz Geode Large space allows larger crystals Fig. 2.12 Chip Clark

35. Ionic Radii Determine Packing Geometry Fig. 2.13

36. Ionic Radius and Charge

37. Graphite Atomic Structure Crystal Form Ken Lucas, Visuals Unlimited Fig. 2.15a

38. Diamond Atomic Structure Crystal Form E.R. Degginger, Photo Researchers Fig. 2.15b

39. Polymorphs • Minerals with the same chemical composition but different structure. • e.g., diamond and graphite • andalusite, kyanite, and sillimanite

40. Polymorphs of Carbon P.L. Kresan

41. There are some 3,500 recognized minerals found on Earth. However, For our purpose, we can focus on about a dozen. Silicates - Si, O and other elements, the most abundant mineral group in the Earth’s crust Carbonates - Ca, Mg and CO3 Salts - NaCl Minerals: lots and lots of ’em

43. Four oxygens surrounding a silicon ion. These tetrahedra combine to make the framework of the silicates. Different combinations produce different structures. Silica-oxygen tetrahedra

44. Silicate Ion[SiO4] 4+ Fig. 2.16a

45. Fig. 2.16b

46. Olivine Chip Clark Isolated Tetrahedra Silcate (example: olivine) Fig. 2.17a

47. Fig. 2.17

48. Sheet Silicate (example: mica) Fig. 2.17d

50. Framework Silicate(example: quartz) Fig. 2.18