definition of a mineral 2.2 minerals 1. naturally occurring 2. solid substance 3. orderly...

Definition of a Mineral

2.2 Minerals

1. Naturally occurring

2. Solid substance

3. Orderly crystalline structure

4. Definite chemical composition

5. Generally considered inorganic

How Minerals Form

2.2 Minerals

1. Crystallization from magma

2. Precipitation

3. Pressure and temperature

4. Hydrothermal solutions

Mineral Groups Can be classified based on their

composition

2.2 Minerals

1. Silicates• Silicon and oxygen combine to form a structure

called the silicon-oxygen tetrahedron. This provides the framework of every silicate mineral.

• Ex. Quartz, Feldspar, Olivine, Mica

The Silicon-Oxygen Tetrahedron

Mineral Groups

2.2 Minerals

2. Carbonates• Contain the elements carbon, oxygen, and one

or more other metallic elements• EX. Calcite, Dolomite

3. Oxides• Contain oxygen and one or more other

elements, which are usually metals• Ex. Corundum, Hematite

2.2 Minerals

4. Sulfates and Sulfides• Contain the element sulfur• Sulfates also contain Oxygen• Ex. Galena, Pyrite, Sphalerite

5. Halides• Contain a halogen ion plus one or more other

elements• Ex. Fluorite, Halite

6. Native elements• Exist in relatively pure form• Ex. Gold, Diamond, Lead, Silver

Color

2.3 Properties of Minerals

Small amounts of different elements can give the same mineral different colors.

Streak is the color of a mineral in its powdered form.

Streak

Luster

2.3 Properties of Minerals

Luster is used to describe how light is reflected from the surface of a mineral.

Pyrite (Fool’s Gold)

Think “shiny” and “dull”

Crystal Form

2.3 Properties of Minerals

Crystal form is the visible expression of a mineral’s internal arrangement of atoms.

Hardness

2.3 Properties of Minerals

Hardness is a measure of the resistance of a mineral to being scratched.

Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest).

Cleavage

2.3 Properties of Minerals

Cleavage is the tendency of a mineral to cleave, or break, along flat, even surfaces.

Fracture

2.3 Properties of Minerals

Fracture—the uneven breakage of a mineral

Density

2.3 Properties of Minerals

Density = Mass / Volume

Distinctive Properties of Mineralsfluorescence, optical properties, radioactivity, magnetism, taste, and reactions to chemicals.

To be classified as a mineral a substance must

meet all of the following characteristics: • Inorganic (not formed by life processes)• Formed in nature (synthetic substances are not

considered minerals)• Solid• Atoms have the same crystalline pattern

(crystal shape is visible, but few are perfect).• Identifiable chemical composition (has the

same kinds of atoms arranged throughout in the same way and in the same proportions).

In summary, a mineral is a naturally occurring, inorganic solid that has a definite chemical composition and crystal structure.

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How common are minerals?How common are minerals?

• There are about 3500 known minerals

• The 20 most common minerals make up 95% of the Earth’s crust

• ALL rocks are composed of minerals

Aquamarine

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MINERAL USE

copper electrical wiring, coins

gold computer circuitry , UV protection for astronauts

magnetite natural magnet

halite table salt

fluorite toothpaste

galena car batteries, iron extraction

molybdenite steel and soil additive

sulfur matches

zeolite water softener

diamond drills

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Rocks

3.1 The Rock Cycle

Rocks are any solid mass of mineral

3 Types of Rocks

1. Igneous rock - formed by the crystallization of molten magma.

Rocks

3.1 The Rock Cycle

Types of Rocks2. Sedimentary rock - formed from the

weathered products of preexisting rocks that have been compacted, and cemented.

3. Metamorphic rock - formed by the alteration of pre-existing rock deep within Earth by heat and pressure

The Rock Cycle

3.1 The Rock Cycle

Rock Cycle shows the interrelationships among the three rock types

Energy That Drives the Rock Cycle

1. Heat from the Earth’s interior

2. Energy from the sun

- powers weathering processes

Formation of Igneous Rocks

3.2 Igneous Rocks

1. Intrusive igneous rocks are formed when magma hardens beneath Earth’s surface. Cools very slowly!Ex. Granite *larger crystals

2. Extrusive igneous rocks are formed when lava hardens. Cools quickly! Ex. Obsidian *smaller crystals

Classification of Igneous Rocks

3.2 Igneous Rocks

1. Texture

Classified based on composition & texture.

• Coarse-grained texture is caused by slow cooling resulting in larger crystals.-intrusive

• Fine-grained texture is caused by rapid cooling resulting in smaller, interconnected mineral grains.- extrusive

Classification of Igneous Rocks

Formation of Sedimentary Rocks

3.3 Sedimentary Rocks

• Erosion involves the weathering and the removal of rock.

• Deposition occurs when an agent of erosion—water, wind, ice, or gravity—loses energy and drops sediments.

Formation of Sedimentary Rocks

3.3 Sedimentary Rocks

• Compaction is a process that squeezes, or compacts, sediments.

• Cementation takes place when dissolved minerals are deposited in the tiny spaces among the sediments. (holds the material together like glue)

Classification of Sedimentary Rocks

3.3 Sedimentary Rocks

1. Clastic sedimentary rocks are composed of weathered bits of rocks and minerals.

• Classified by particle size

- Shale, Sandstone, Conglomerate

• Common rocks include

Classification of Sedimentary Rocks

3.3 Sedimentary Rocks

2. Chemical sedimentary rocks form when dissolved substances precipitate, or separate, from water. • Common rocks include

-Limestone, Coal

3.3 Sedimentary Rocks

Features of sedimentary rocks are clues to how and where the rocks are formed

Formation of Metamorphic Rocks

3.4 Metamorphic Rocks

Metamorphism means “to change form.”

Conditions for formation are found a few kilometers below the Earth’s surface and extend into the upper mantle.

Most metamorphic changes occur at elevated temperatures and pressures.

Formation of Metamorphic Rocks

3.4 Metamorphic Rocks

Contact metamorphism occurs when magma moves into rock.

Regional metamorphism results in large-scale

deformation and high-grade metamorphism.

Agents of Metamorphism

3.4 Metamorphic Rocks

Heat

Pressure

• Provides the energy needed to drive chemical reactions

• Causes a more compact rock with greater density

Classification of Metamorphic Rocks

3.4 Metamorphic Rocks

1. Foliated Metamorphic Rock

2. Nonfoliated Metamorphic Rock

Two main categories

• Has a banded or layered appearance• Ex. Gneiss

• Does not have a banded texture• Ex. Marble

Classification of Metamorphic Rocks

This process can take billions of years!

Rock Cycle Song(Sing to the tune of "Row, Row, Row Your Boat")

SEDIMENTARY rockHas been formed in layersOften found near water sourcesWith fossils from decayers

Then there's IGNEOUS rockHere since Earth was bornMolten Lava, cooled and hardenedThat's how it is formed

These two types of rocksCan also be transformedWith pressure, heat and chemicalsMETAMORPHIC they'll become.( Don't forget to sing this as a "Round"; after all, it is the Rock "Cycle"! )