ES 9a.Students know the resources of major economic importance in California and their relation to California

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Ch 5. Minerals

• ES 9a.Students know the resources of major
  economic importance in California and their
  relation to Californias Geology.

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Characteristics of Minerals

• To be a mineral, a substance must have four
  characteristics
• must be inorganicit cannot be made of or by
  living things
• must occur naturallyit cannot be man-made
• must be a crystalline solid
• must have a consistent chemical composition.

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Kinds of Minerals

• All minerals can be classified into two main
  groups based on their chemical compositions.
• silicate mineral contains a combination of
  silicon and oxygen, may also contain one or more
  metals
• Silicate minerals make up 96 of Earths crust.

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• nonsilicate mineral does not contain compounds of
  silicon and oxygen
• Make up about 4 of Earths crust.

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Physical Properties of Minerals

• Color
• is unreliable for the identification of minerals.
• can be affected by impurities or by weathering
  processes.
• Streak
• the color of a mineral in powdered form
• determined by rubbing some of the mineral against
  an unglazed ceramic tile called a streak plate.

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• Luster
• the way in which a mineral reflects light
• metallic luster if it reflects light
• All other minerals have nonmetallic luster.
• Ex. glassy, waxy, pearly, brilliant, and earthy.

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• Cleavage
• the tendency of a mineral to split along specific
  planes of weakness to form smooth, flat surfaces
• Fracture
• the manner in which a mineral breaks along either
  curved or irregular surfaces

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Physical Properties of Minerals

• Hardness
• the ability of a mineral to resist scratching is
  called hardness.
• Mohs hardness scale the standard scale against
  which the hardness of minerals is rated.
• The strength of the bonds between the atoms that
  make up a minerals structure determines the
  hardness of a mineral.

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Ch 6 ROCKS

• Students know how to explain the properties of
  rocks based on the physical and chemical
  conditions in which they formed, including plate
  tectonic processes

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Three Major Types of Rock

• Rock The material that makes up the solid parts
  of Earth.
• Rocks are classified based on the processes that
  form.

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3 Types of Rocks

1. Igneous rock forms when magma, or molten rock,
   cools and hardens.
2. Sedimentary rock forms when sediment deposits
   that form when rocks, mineral crystals, and
   organic matter have been broken into fragments
   are compressed or cemented together.
3. Metamorphic rock forms when existing rock is
   altered by changes in temperature, pressure, or
   by chemical processes.

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The Rock Cycle
Chapter 6

• Geologic forces and processes cause rock to
  change from one type to another.
• rock cycle the series of processes in which rock
  forms, changes from one form to another, is
  destroyed, and forms again by geological
  processes

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The Formation of Magma
Chapter 6

• igneous rock rock that forms when magma cools and
  solidifies
• The three factors that affect whether rock melts
  include
• 1) temperature,
• 2) pressure,
• 3) the presence of fluids in the rock.

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The Formation of Magma, continued
Chapter 6

• Partial Melting
• Different minerals have different melting points
• As the temperature increases and as other
  minerals melt, the magmas composition changes.

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The Formation of Magma, continued
Chapter 6

• Fractional Crystallization
• The crystallization and removal of different
  minerals from the cooling magma.
• Minerals that have the highest freezing points
  crystallize first.

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Textures of Igneous Rocks
Chapter 6

• intrusive igneous rock rock formed beneath
  Earths surface
• extrusive igneous rock rock formed at Earths
  surface

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Textures of Igneous Rocks, continued
Chapter 6

• Coarse-Grained Igneous Rock
• Because intrusive igneous rocks cool slowly, they
  commonly have large mineral crystals.
• Fine-Grained Igneous Rock
• Because extrusive igneous rocks cool rapidly,
  they are commonly composed of small mineral
  grains.

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Sedimentary Rock

1. Rocks, mineral crystals, and organic matter that
   have been broken into fragments .
2. Sediment is carried away and deposited by water,
   ice, and wind.
3. Sediment deposits are compressed or cemented
   together and harden they form sedimentary rock.

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Chemical Sedimentary Rock
Section 3 Sedimentary Rock
Chapter 6

• chemical sedimentary rock sedimentary rock that
  forms when minerals precipitate from a solution
  or settle from a suspension

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Organic Sedimentary Rocks
Section 3 Sedimentary Rock
Chapter 6

• organic sedimentary rock sedimentary rock that
  forms from the remains of plants or animals

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Organic Sedimentary Rocks, continued
Section 3 Sedimentary Rock
Chapter 6

• The diagram below shows the formation of organic
  limestone.

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Clastic Sedimentary Rock
Section 3 Sedimentary Rock
Chapter 6

• clastic sedimentary rock sedimentary rock that
  forms when fragments of preexisting rocks are
  compacted or cemented together

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Formation of Metamorphic Rocks
Chapter 6

• One type of rock changes into metamorphic rock
  because of chemical processes or changes in
  temperature and pressure
• Heat, pressure, and hot fluids cause some
  minerals to change into other minerals.

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Formation of Metamorphic Rocks, continued
Chapter 6

• Contact Metamorphism
• A change in the texture, structure, or chemical
  composition of a rock due to contact with magma
• Regional Metamorphism
• A change in the texture, structure, or chemical
  composition of a rock due to changes in
  temperature and pressure over a large area,
  generally are a result of tectonic forces

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Classification of Metamorphic Rocks
Chapter 6

• Foliated Rocks
• Minerals grains are arranged in planes or bands
• Extreme pressure may cause the mineral crystals
  in the rock to realign or regrow to form parallel
  bands.

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Classification of Metamorphic Rocks, continued
Chapter 6

• Nonfoliated Rocks
• Minerals grains are not arranged in planes or
  bands