Bingham Copper Mine, UT

World’s largest mine

1 mile deep, 3 miles wide

Atoms

Compound

To make a compound, you bond cations (+) to anions (-)Compound has specific internal structure

Ionic Bonding

Gain or lose an electronElectrons used in bonding -- the “glue”

Covalent Bonding

A mineral’s outward appearance is a reflection of its internal structure

Fluorite Halite (salt) Calcite

Physical Properties

Physical properties depend on a mineral’s internal structureand chemical composition.

HardnessCleavageLusterColorSpecific Gravityetc…

Silicon Tetrahedron

Silicon Oxygen

Basic buildingblock of >90%of minerals

1 Si4 O------SiO4

Pyramid shape

“Silicate Minerals”

Most abundant elements

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Silicate Minerals

Silicate MineralsSi tetrahedrons

Ionic Substitution

When 2 or more ions substitute for each other in a mineral structure.

For example, in the mineral olivine (Mg,Fe)2SiO4, ions of Fe and Mg can substitute freely for each other.

The total number of Fe ad Mg ions is constant in relation to Si and O, but the ratio of Fe/Mg may vary from sample to sample.

Ions must have same charge and be similar in size.

Polymorphism

Same chemical formula, different chemical structure

Example: Graphite “C” and Diamond “C”

Graphite

Surface environment: Low pressure, low temperature

Diamond

High pressure, high temperature

Non-Silicate MineralsOther important minerals are: - Calcite CaCO3: Important mineral in fossils and shells of sea creatures - Clay minerals: Make up the finest sediment in rivers and streams - Halite NaCl: Table salt - Native Elements: Au, Cu, Ag, Pt, C (diamond and graphite) Gemstones: - diamond C - emerald from a mineral called Beryl - Opal - Ruby & Sapphire from Corundum - Amethyst from quartz (SiO2) - Topaz - Jade - Garnet Sulfides: - galena PbS - lead - sphalerite ZnS - zinc - pyrite FeS2 - fools gold - penlandite for Ni, Pt- chalcopyrite CuFeS2 - copper

New Cornelia Mine, AZ

1000’ deep

Cyanide leakage

Cyanide is used to leach metalsout of tailings piles.

Cyanide pit

Acid DrainageSummitville, CO:All aquatic life absent for17 miles away from mine.

How bad is it?

Tintic Mountains, Utah

Reclaimed coal mine, PA

Site refilled, lined with thick plastic