Transcript The Rock Cycle

The Rock Cycle
Minerals
• A natural occurring
solid with a crystalline
structure.
• Nonliving.
• Quartz, diamond, and
salts are all minerals.
• Used in jewelry.
Mineral Properties
• Color: Minerals come in a
rainbow of colors.
• Streak: The color of the
powder left behind when
you rub a mineral against
a rough white tile. It does
not vary.
• Luster: The way a mineral
reflects light. Many
minerals have a metallic
luster.
Mineral Hardness
• A mineral’s ability to resist
being scratched.
• Some minerals can not
be scratched by anything.
• The softest mineral is talc
and is classified by a ‘1.’
• The hardest minerals are
diamonds and they are
classified by a ’10.’
Detecting Hardness
• Hardness is
determined using the
Mohs’ scale.
• The scale goes from
1 to 10. Any mineral
that is higher on the
scale can scratch any
mineral lower on the
scale.
Example
• Suppose you have a
mineral whose
hardness is unknown.
• A steel nail (hardness
of 5.5) can not
scratch the mineral,
but a piece of quartz
(hardness of 7) can.
What is the hardness
of this mineral?
Answer
• Suppose you have a
mineral whose
hardness is unknown.
• A steel nail (hardness
of 5.5) can not
scratch the mineral,
but a piece of quartz
(hardness of 7) can.
What is the hardness
of this mineral?
• The mineral has a
hardness between 5.5
and 7 since a steel
nail could not scratch
it but a quartz could.
Special Properties
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Magnetism
Fluorescence
An Electrical Charge
Produces a double
image
Rocks
• A natural solid made
of one or more
minerals.
• Mountains, valleys,
hills, beaches, and
the ocean floor are
made of rocks.
Igneous Rocks
• Rock that forms when
melted rock cools and
hardens.
• Can form underground or
on the Earth’s surface.
• When formed
underground igneous
rocks have large crystals.
• When formed on Earth’s
surface they have small
or no crystals.
Sedimentary Rocks
• Pieces of sediment that
have been pressed and
cemented together.
• Pieces of sediment settle
out of water or wind
during deposition. This
leads to the formation of
sedimentary rocks.
• Forms from any worn
down rock.
Metamorphic Rocks
• Rock changed by
heat and pressure.
• Can form from any
other rock.
• Found in every
mountain range on
Earth.
• Found in the ocean
and near some
volcanoes.
Examples
Draw a line to match.
• Igneous Rocks
• Sedimentary Rocks
• Metamorphic Rocks
How Rocks are Used
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A natural resource.
Sandpaper.
Buildings.
Monuments.
The US Capitol
building uses
sandstone and
marble.
Processes that Change Rocks
• Weathering is a process
of breaking down rocks
into sediment.
• All rocks on the Earth’s
surface are weathered.
Wind and water also
weathers rocks.
• The process of wearing
away and removing
sediment by wind, water,
or ice is called erosion.
The Rock Cycle
• A continuous process
in which one type of
rock changes into
another.
• Weathering, erosion,
deposition, heat, and
pressure can all
change rocks.
Science Up Close
• Earth recycles rocks
through the rock
cycle.
• Heat and pressure
can change one type
of rock to another.
Soil Formation
• Soil can be formed from
weathered rock under it
or from eroded sediment
carried from far away.
• Soil contains minerals.
• Most soil is made up of
more than just weathered
rock.
• Farm soil contains small
pieces of decayed plants
and animals called
humus.
Summary
• The Rock Cycle is a
group of changes.
Igneous rock can change
into sedimentary rock or
into metamorphic rock.
Sedimentary rock can
change into metamorphic
rock or into igneous rock.
Metamorphic rock can
change into igneous or
sedimentary rock.
Questions
• What are minerals?
• What are three visible properties of
minerals?
• How can you determine a mineral’s
hardness?
• How do rocks form?
• How are rocks changed?