1. chemistry - elements, electronic structure, bonding, chemical analyses; forms of x-tals
2. physics - physical properties (density, electrical properties, cleavage, hardness, magnetic properties, etc.)
3. crystallography - the structure of minerals - internal & external; geometry and trigonometry; symmetry
4. mineral genesis - environments of formation (e.g., ocean floor vs. subduction zone)
5. determinitive mineralogy - physical and chemical testing; analytical equipment
6. classification schemes
7. interrelationships between humans and their natural environment

Mineral: a naturally occurring, homogeneous solid with a definite, but generally not fixed, chemical composition and ordered atomic arrangement

- usually formed by inorganic processes (i.e., coal is not a mineral)
- definite chemical composition (some atomic substitution allowed)
- "ordered atomic arrangement" - eliminates liquids and gases
    also eliminates amorphous solids such as glass and obsidian

    note : opal SiO₂nH₂0 - silica spheres are amorphous, but are arranged
    in a close packed geometry, therefore opal is considered a mineral

Earth's crust:
compostion - 95% igneous rock (or it's metamorphic equivalent) - e.g., basalt, granite, granitic gneiss, schist...
8 most abundant elements in crust = (99 weight % and approx. volume) O, Si, Al, Fe, Ca, Na, K, Mg

Most common crustal minerals are:

- silicates - e.g., quartz SiO₂
- aluminosilicates - e.g., K-feldspar (orthoclase) KAlSi₃O₈
- oxides - e.g., hematite Fe₂O₃

Total earth:
composition - 99% Fe, O, Si, Mg, Ni, S, Ca, Al

- difference due to core and mantle

Fe, Mg-silicates = mantle
S, Ni, Fe = core

http://classes.colgate.edu/rapril/geol201/ Questions to: rapril@mail.colgate.edu Copyright 1997 © Colgate University.

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