Minerals

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Minerals Rocks
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Minerals

• A naturally formed, inorganic solid with crystal
  structure and definate chemical composition.
• The substance was not formed by or from living
  things such as plants or animals
• Made from Chemical elements or compounds
• Minerals can be identified by their physical and
  chemical properties
• Luster, Streak, Crystal,Hardness, Density and
  Structure.

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Luster

• The way a mineral reflects light
• Metallic Luster
• hard, shiny
• Nonmetallic Luster
• shiny, glassy, waxy, pearly, earthy (dull)

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Streak

• The streak is the color of the mineral in
  powdered form.
• The streak is found by rubbing a fresh corner of
  the mineral across a white, unglazed streak plate
• Some metallic minerals leave behind a powder
  that is not the same color as the mineral.
• The color of the mineral is not always the same
  as the streak! Streak is more reliable.

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Crystal Structure

• A regularly shaped solid formed by an repeating
  ordered pattern of atoms
• Examples include Six sided, cubic, rectangular,
  sheets, fibers

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Hardness

• A measure of how easily a mineral can be
  scratched.
• Minerals can be tested by scratching the unknown
  mineral with the edge or point of other materials
  of known harness

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Mohs Scale of Hardness
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Density

• Can be found by either dividing the mass of a
  sample by its volume or flotation
• Waters density is 1 g/mL
• A substance will sink in water if it is more
  dense than 1g/mL and float if it is less dense
  than 1g/ML

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Rocks

• Nearly all rocks are composed of one or more
  minerals
• Geologists classify rocks according to how they
  were formed
• Igneous rocks form from lava when it reaches the
  surface, cools and solidifies
• Sedimentary rocks result from the compaction and
  cementing of layers of sediment
• Metamorphic rocks form when other types of rocks
  are changed by heat and/or pressure

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Igneous Rocks

• The result of the solidification of magma or lava
• Most lack layering, however successive lava flows
  can form a layered rock structure
• Those that cool slowly, deep within Earth, are
  composed of large crystals
• Those that cool faster, at or near the Earths
  surface, have smaller or no visible crystals

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Igneous Rock Formation
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Igneous Rock Classification
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Sedimentary Rocks

• Most are composed of the weathered remains of
  other rocks
• Usually are formed by the compression and
  cementing of particles of sediment
• Generally exist as a thin layer over
  metamorphic and igneous rocks

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Sedimentary Rock Characteristics

• Fragmental rocks are made up of different sized
  particles such as shale, sandstone and
  conglomerate (composed of pebbles or larger
  stones held together by natural cement)
• Organic sedimentary rock contain the accumulation
  of plant and animal remains
• Fossils are commonly found
• Chemical sedimentary rocks are deposited by the
  settling of materials from solution in seawater
• This occurs during the evaporation of seawater
  and when chemical reactions in the water form
  compounds that settle
• Rock Salt is an example

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Sedimentary Rock Classification
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Metamorphic Rocks

• Form when sedimentary and igneous rocks are
  changed by heat and/or pressure
• The only kind of rock that forms directly from
  another rock
• Metamorphism may cause structures, such as
  layering, to become distorted or to disappear
• It also may cause new minerals to form, and/or
  crystals to grow
• Most are formed deep within the Earth and pushed
  to the surface when mountains are formed

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Metamorphic Rock Classification

• Texture
• Appearance and feel of the rock surface
• Grain Size
• Composition
• Type of Metamorphism

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Metamorphic Rock Classification
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The Rock Cycle

• Natural changes in rocks and rock material that
  takes place at the Earths surface and within
  Earth
• Nearly all rocks are made from the remains of
  other rocks
• Rocks are classified based of their origin
• Rocks can change in response to changing
  conditions at the surface or within Earth

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The Rock Cycle