Classification of Minerals

Possibilities?

Chemical composition

Gold, Silver, Sulfur

Native elementsAu, Ag, S

SulfidesPyrite, Galena FeS, PbS

Hematite, Magnetite Fe2O3, Fe3O4

Oxides

Silicates Quartz, Mica, Feldspar

SiO2

KAl2(AlSi3O10)(OH,F,Cl)2

KAlSi3O8

Silic- is for Silicon (s)

Silicates

-ate is a suffix for “oxide “

Silicates are “oxides of silicon”

Quartz Mica

KAl2(AlSi3O10)(OH,F,Cl)2SiO2

Can you find the “silica” ?

Silicates

Silica Structure

4 oxygen atoms for every 1 silicon atom

Olivine

Feldspar, Quartz

Micas

Amphibole (Hornblende)

Pyroxenes (Augite)

Complexity Temp.

Chemical formula:

CChemical formula:

C

Graphite Diamond

How can 2 minerals with the same composition be so different?

What’s the point here?

“Internal Arrangement of Atoms” controls most physical properties!

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…..

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!

Quartz Muscovite Mica