1. Classification of Minerals
By Jessica Marcus

2. Chemical composition Native elements Gold, Silver, Sulfur Au, Ag, S
Pyrite, Galena
FeS, PbS
Sulfides
Hematite, Magnetite
Fe2O3, Fe3O4
Oxides
SiO2
KAl2(AlSi3O10)(OH,F,Cl)2
KAlSi3O8
Quartz, Mica, Feldspar
Silicates

3. Silic- is for Silicon (s)
Silicates
Silic- is for Silicon (s)
-ate is a suffix for “oxide “
Silicates are “oxides of silicon”
Look at the reference table and calculate the weight of silicon and oxygen.

4. Silicates Mica Quartz Can you find the “silica” ? SiO2
KAl2(AlSi3O10)(OH,F,Cl)2
Can you find the “silica” ?

5. Silica Structure
4 oxygen atoms for every 1 silicon atom

6. Complexity
Temp.
Olivine
Pyroxenes (Augite)
Amphibole (Hornblende)
Micas
Feldspar, Quartz

8. How can 2 minerals with the same composition be so different?
Graphite
Diamond
Chemical formula: C
Chemical formula: C
How can 2 minerals with the same composition be so different?

9. “Internal Arrangement of Atoms” controls most physical properties!
What’s the point here?
“Internal Arrangement of Atoms” controls most physical properties!

10. Review of Concepts: 1. Minerals can be identified by examining…..
Physical Properties, including….
Luster, Hardness, Cleavage, Color, Streak, Density….
2. Minerals are classified according to their…..
Chemical Composition, including groups like….
Native Elements, Sulfides, Oxides, and the all important SILICATES
3. The “Basic Building Block” of the Silicate Minerals is…..

11. Review of Concepts: (continued)
4. The physical properties of minerals are generally controlled by…..
Crystalline Structure….
…or the “orderly internal arrangement of the atoms”!
What do graphite and diamond have in common?……
Identical Chemical Composition….
What accounts for the differences between graphite and diamond?
….the “orderly internal arrangement of the atoms!

12. Quartz
Muscovite Mica