1. CH. 2 - MINERALS

2. MINERALS
Basic building block of rocks
>4,000 minerals identified
Mineral Definition (requirements):
1) Solid
2) Naturally Occurring

3. Mineral Definition
3) Inorganic – no biologic origin
4) Definite Chemical Composition
Ex: Halite =
Quartz =
Diamond =
Graphite =

4. Mineral Definition
5) Ordered Crystalline Structure
Ex: Halite (NaCl)

5. Ordered Crystalline Structure
Diamond = high pressure
- complex bonding of carbon
atoms
Graphite = low pressure
- carbon atoms bond in sheets

6. Diamond structure

7. Graphite structure

8. Mineral Definition
1. Solid
2. Naturally Occurring
3. Inorganic
4. Definite Chemical Composition
5. Ordered Crystalline Structure

9. Structure of Minerals
1) Atom – smallest building block of
an element
Composed of atomic particles
- protons (+)
- neutrons
- electrons (-)

10. Periodic Table of the Elements
(p. 31)

11. Balanced Atoms
Atomic Number = number of
protons
- defines which element atom
belongs to
Atomic Mass = sum of protons &
neutrons

12. Balanced Atoms
Number of electrons = number of
protons
Rule:
1st energy level = 2 electrons max
All other energy levels = 8
electrons max

13. Atomic Structure

14. Balanced Atoms
Valence electrons = electrons in
outermost energy level
Atoms bond b/c they want full
outer shell of electrons

15. Types of Bonding
1) Ionic Bonding
Ion = atom with an electrical
charge
- caused by losing or gaining
electrons

16. Ionic Bonding
Atoms bond b/c opposites attract
(like magnets)
Ex: Halite (NaCl)

17. Types of Bonding
2) Covalent Bonding
- atoms share valence electrons
- outer energy levels overlap
Ex: Oxygen (O2)

18. Oxygen

19. Structure of Minerals
2) Element – composed entirely of
same kind of atoms
- all atoms have same number of
___________
92 naturally occurring elements

20. Element
Some minerals are elements:
Ex: Native Copper
Gold
Sulfur
Graphite

21. Structure of Minerals
3) Compound – combination of
two or more elements
- characteristics are different than
individual elements
Ex: Halite NaCl

22. Compound
Most minerals are compounds:
Quartz = SiO2
Galena = PbS (lead sulfide)
Hematite = Fe2O3 (iron
oxide)

23. Chemical Composition of Crust
98.3% of crust composed of 8
elements (Figure 2.21)
Other 84 elements share 1.7% of
remaining crust
- includes

24. Crustal Composition

25. Mineral Groups
1) Silicate Group - 90% of all
minerals
Basic building block is the silica
tetrahedron SiO44-

26. Silica tetrahedron (SiO44-)
Negative charge bonds with
positive ions
Other abundant elements of crust
are positive ions

27. Mineral Groups
2) Nonsilicate Group
Includes:
a) rock-forming minerals
Ex: calcite

28. Nonsilicate Group
b) native elements
Ex: sulfur, copper, gold
c) Metal ores
Ex: galena (PbS)
magnetite (Fe3O4)

29. Rocks
Aggregate of minerals (mixture)
Some rx are impure quantities of
the same mineral
Ex: Limestone = calcite
(rock) (mineral)

30. Rocks
Most rx are composed of several
minerals
Ex: Granite = quartz, feldspar,
(rock) hornblende
(minerals)

31. Granite & its minerals

32. 3 groups of rocks
1)
2)
3)