Minerals

5 characteristics 1. Naturally occurring 2. Solid 3. Orderly crystalline structure 4. Definite chemical composition 5. Generally inorganic

Mineral Formation - Four Major Processes 1.Crystallization from magma first minerals to crystallize are those rich in Iron, Calcium and Magnesium as minerals form the composition of magma changes and minerals rich in Sodium, Potassium, and aluminum then form

2. Precipitation occurs when water evaporates Changes in water temp. also causes minerals to be left behind, called precipitates 2 example s are Limestone and Halite

3. Pressure and Temperature formed when existing minerals are subject to Pressure and Temperature Pressure causes atoms to rearrange in a more compact form Temperature causes some minerals to become unstable the new mineral are now stable

4. Hydrothermal solutions a very hot solution of water and dissolved substances hydrothermal solution have temperature between 100 and 300 degrees Celsius a chemical reaction causes new minerals to form

Mineral Groups 6 major groups of minerals based on chemical composition

Silicates – most common formed from Silicon and Oxygen 1 Silicon atom and 4 oxygen atoms form the shape of a Tetrahedron. This is the framework for all silicates

Silicon – Oxygen tetrahedron can be joined in many configurations Single - tetrahedral (ex: olivine) Single chain (ex: augite) Double chain (ex: Hornblende) Sheets (ex: micas) 3D framework (ex: quartz and feldspar) Formation occurs when magma cools  Place and chemical composition determine structure

Carbonates – 2 nd most common contain the elements Carbon, Oxygen and 1 other metallic element most common carbonate is Calcite examples of carbonates are Dolomite

Oxides minerals that contain Oxygen and 1 other element examples of oxides are Rutile, Corundum, Hematite various ways of forming: Temperature, Pressure, exposure to water, moisture in the air

Sulfates and Sulfides contain the element Sulfur examples of sulfates and sulfides are anhydrite, gypsum various ways of forming: evaporating mineral rich water (precip), and hydrothermal solutions

Halides contain a halogen Halogens are in group 17 of the Periodic Table examples of halogen are halite, fluorite

Native Elements a. minerals that contain only 1 element b. examples of native elements are gold, silver, graphite