2. Minerals: Building Blocks of Rocks
Definition of a mineral
Natural
Inorganic
Solid
Possess an orderly internal structure of atoms
Have a definite chemical composition
Rock – any naturally occurring solid mass of mineral or mineral-like matter

3. Rocks are Aggregates of Minerals

4. Atoms: Building Blocks of Minerals
Smallest particles of matter

5. Atomic Structure Nucleus – central part of an atom that contains
Protons – positive electrical charges
Neutrons – neutral electrical charges
Electron shells
Surround nucleus
Contain electrons – negative electrical charges

6. Atomic Structure

7. Atoms Atomic number Ions Number of protons in an atom’s nucleus.
Positively or negatively charged atoms due to electron gain or loss

8. Composition and Structure of Minerals
Elements
Basic building blocks of minerals
Over 100 are known
Defined by their number of protons
Groups of the same type of atoms

9. Periodic table of the elements

10. Atomic Bonding Valence shell Octet rule Chemical bond
An atom’s outermost shell
Octet rule
Atoms gain, lose, or share electrons until their valence shells have 8 electrons
Chemical bond
Transfer or sharing of electrons to achieve full valence shell

11. Atomic Bonding Ionic bond
Atoms bond together when oppositely charged ions attract

12. Atomic Bonding Covalent bond
Sharing of a pair of electrons between atoms

13. Atomic Bonding Metallic bond
Packed metal atoms have valence electrons free to move throughout the structure.

14. Minerals Physical properties of minerals Habit – common crystal shape
Luster – appearance in reflected light
Color
Streak – color of mineral in powdered form
Hardness – ability to resist scratching or abrasion
Cleavage – tendency to break along planes of weak bonding

15. Metallic Luster: Galena

16. Color
Color can be unreliable due to variations.

17. Streak

18. Crystal Shape, or Habit: Pyrite

19. Hardness: Mohs Scale

20. Cleavage: Micas

21. Minerals Physical properties of minerals
Fracture – random pattern of breakage
Specific gravity – mineral density
Tenacity – resistance to cutting, breaking, bending, and deformation

22. Conchoidal fracture

23. Minerals Other properties Taste Smell Elasticity Malleability
Double refraction
Magnetism
Feel
Reaction with hydrochloric acid

24. Mineral Groups Rock-forming minerals Only a few dozen
Most abundant atoms in Earth’s crust are oxygen (46.6% by weight) and silicon (27.7% by weight)

25. Mineral Groups Eight elements compose most rock-forming minerals:
oxygen (O),
silicon (Si),
aluminum (Al)
iron (Fe)
calcium (Ca)
sodium (Na)
potassium (K)
magnesium (Mg)

26. Composition of Continental Crust

27. Mineral Groups Rock-forming silicates Most common mineral group
Contain the silicon-oxygen tetrahedron
Four oxygen atoms surrounding a much smaller silicon atom
Combines with other atoms to form the various silicate structures

28. Mineral Groups Rock-forming silicates
Groups based upon tetrahedral arrangement
Olivine – independent tetrahedra
Pyroxene group – tetrahedra are arranged in chains
Amphibole group – tetrahedra are arranged in double chains

29. Hornblende: An Amphibole

30. Mineral Groups Rock-forming silicates
Groups based upon tetrahedral arrangement
Micas – tetrahedra are arranged in sheets
Two types of mica are biotite (dark) and muscovite (light)
Feldspars – Three-dimensional network of tetrahedra

31. Mineral Groups Rock-forming silicates
Groups based upon tetrahedral arrangement
Feldspars – most abundant group of minerals in Earth’s crust
Quartz – three-dimensional network of tetrahedra

32. Potassium feldspar

33. Rose Quartz

34. Mineral Groups Nonsilicate minerals – major groups Oxides Sulfides
Carbonates
Halides
Native elements

35. Common Nonsilicate Mineral Groups

36. Minerals Mineral groups Nonsilicate minerals Carbonates
A major rock-forming group
Found in the rocks limestone and marble
Halite and gypsum are found in sedimentary rocks
Many have economic value

37. Natural Resources Renewable Nonrenewable
Can be replenished in relatively short time spans
Corn, wind, water, etc.
Nonrenewable
Earth has fixed quantities
Oil, aluminum, natural gas, coal

38. Natural Resources Mineral resources
Mineral resources are occurrences of useful minerals that will eventually be extracted
Ore deposits are concentrations of metallic minerals that can be mined at a profit
Economic factors may change and influence a resource

39. Copper Mining