1. Introduction to Minerals
Created By:
Mr. Kreeger

2. Homework and Page References
HW # on page 37 of text
HW # on page 41 of text
HW # 3- Explain what gives minerals their external features and how does their atomic structure affect this?

3. Table of Contents Minerals Defined Characteristics of Minerals
Mineraloids
Industrial Minerals
Biochemical Minerals
Characteristics of Minerals
Crust Composition
Examples of Various Mineral Compositions
Crystalline Form

4. Introduction to Minerals

5. 1. Minerals Defined
A mineral is the basic material that makes up the earth’s crust and has the following characteristics:
Naturally occurring
Inorganic
Has a fixed chemical composition
Has an orderly internal arrangement of atoms.

6. 1. Minerals
Mineraloids-Lack crystal structure (Examples include rare gemstones)
Industrial Minerals- Used for manufacture of physical materials.
Biochemical Minerals- Can be manufactured by organisms (Example: Aragonite-Made by clams to produce their shells)

7. 2. Characteristics of Minerals
Naturally Occurring- Formed as a result of natural processes in or on the earth
Inorganic- Came from things that were never alive.
Fixed Chemical Composition- Use of a chemical formula or symbol to represent what mineral is made of.
1. Some minerals found as pure elements (Cu, Ag), most are found as compounds (Calcite(CaCO3), Quartz(SiO2).

8. 3. Composition of Crust
**98% of the crust is made of just 8 elements, even though there are over 100 known elements ( Pg 11 of ESRT)
Element
% by Mass
Oxygen
46.40
Silicon
28.15
Aluminum
8.23
Iron
5.63
Calcium
4.15
Sodium
2.36
Magnesium
2.33
Potassium
2.09
Nitrogen
Hydrogen
Other
0.66

9. Composition of Crust

10. 4. Examples of Various Mineral Compositions
Chemical Name
Chemical Formula
Calcite
Calcium Carbonate
CaCO3
Galena
Lead Sulfide
PbS
Gypsum
Calcium Sulfate-Water
CaSO2 +2H2O
Olivine
Magnesium Silicate
Mg2SiO4
K-Feldspar
Potassium aluminum silicate
KAlSi3O8
Pyrite
Iron Sulfide
FeS2
Quartz
Silicon dioxide
SiO2

11. Pictures of Minerals

12. Uses of Minerals

13. 5. Crystalline Form
Atoms or molecules of a mineral are the same throughout that mineral
There is a definite repeating pattern in minerals, if pattern is large enough to be seen it is called a crystal.
Internal structure determines outside structure.

14. 5. Crystalline Form
Isometric- 3 axis of equal length, intersect at 90 degrees (Galena, Halite, Pyrite)
Orthohombic-3 axis of different length, intersect at 90 degrees (Olivine, topaz)

15. 5. Crystalline Form
Triclinic- 3 axis of unequal length that are oblique to one another (Plagioclase Feldspar)
Monoclinic- 3 axis of unequal length, 2 intersect at 90 degree angles, the other is oblique to others (Mica, Gypsum)

16. 5. Crystalline Form
Hexagonal- 3 horizontal axes of same length intersect at 60 degree angles. Vertical axis can either be longer or shorter than horizontal axis. (Calcite)
Tetragonal- 3 axes intersect at 90 degree angles. Two horizontal axes are equal length. Vertical axes is longer or shorter than horizontal axes. (Cassiterite)

17. crystal shape
The shape of the mineral’s crystals as a result of its atomic arrangement