Rocks and Minerals
Study Guide for Test on
Friday, October 17th
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Continental Drift
•Remember that Wegener’s
Theory of Continental Drift
states that the continents were
once joined together as a
super-continent called
Pangaea.
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• Besides the puzzle-like fit of the
continents, the best evidence for
his theory includes similar types
of rocks and fossils, the remains
of a plant or animal that have
been cast in rock.
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Minerals
Minerals are:
• Naturally occurring
• Inorganic (nonliving)
• Solid
• Things that have a definite
composition and crystalline structure
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“Geology Kitchen”
http://www.youtube.om/watch?v=rTXSwnkieZc
Example:
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You try!
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SALT
Solid
Crystal Structure
Inorganic
Vs.
SUGAR
Solid
Crystal Structure
Organic
(comes from something living)
All Minerals
Definite
Chemical
Composition
Naturally Occurring
Made by nature
not by man
Inorganic
NOT made from
once-living
materials
are/have
Solid
Not a liquid or a
gas; particles
packed so tight
they can’t move
Always has
certain
elements
Crystal Structure
Repeated
pattern of
atoms
Answer:
• Salt is the mineral. It meets all the
requirements in the definitions of
mineral.
• Sugar is NOT a mineral. It does not
meet one of the requirements to be a
mineral. Sugar is organic because it
comes from a plant.
Minerals are identified by
using their properties:
•Color
•Luster – the way in which a
mineral reflects light
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• Streak – the color of the powder
of a mineral
• Cleavage – the splitting of a
mineral along smooth, flat
surfaces
• Fracture – the manner in which a
mineral breaks along either
curved or regular surfaces
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•Hardness – a measure of the
ability of a mineral to resist
scratching; Diamond is the
hardest mineral; Talc is the
softest mineral
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Mohs Hardness Scale:
• Measures the
hardness of
minerals &
orders them so
you can see
which mineral
scratches other
minerals.
Use the Mohs Hardness Scale on page
72 to answer the following questions:
1. Would a piece of Apatite scratch a piece of Quartz?
2. What would you expect to happen if you rubbed a
mineral of hardness 8.5 against a piece of Topaz?
3. Which mineral in the Scale will scratch quartz?
4. List the following minerals in order of decreasing
hardness: apatite, fluorite,
diamond, talc, and gypsum.
Answers:
1) No
2) The Topaz would scratch.
3) Topaz, Corundum, Diamond
4) Diamond, Apatite, Flourite,
Gypsum, Talc
•Density – the ratio of the
mass of a substance to the
volume of a substance;
“how much stuff is packed
into a certain amount of
space”
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• Graphite is used to make pencil lead.
Minerals Jam
http://www.youtube.com/watch?v=F0IA21bgmM
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Color
Identify Minerals
Magnetic,
fluorescent,
reactive
Streak
The color
of its
powder
Cleavage
and
Fracture
by
Fracture –
minerals break
irregular
Luster
Way a
surface
reflects
light
Shiny, glassy,
waxy, pearly
Special
Properties
Density
mass in a
given
space
Hardness
Cleavage –
mineral
splits along
flat surfaces
Crystal Systems
How hard
or soft
6 groups of
crystal
shapes
Rocks
• The most useful way to identify a rock
is by its mineral content. Different
colors in rocks are due to the different
minerals in them.
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• Rocks are classified by how they are
formed, and there are three types of rocks
– sedimentary, igneous, and metamorphic.
One type of rock can be changed into
another by undergoing the rock cycle.
When old rock is changed into new rock
during the cycle, it takes a very LONG time.
Not all rocks go through the entire cycle.
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Rock Cycle Clip
http://www.youtube.com/watch?v=pm6cCg_Do6k
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Sedimentary Rocks
• Sedimentary rocks are formed by
weathering (when wind, water, and
ice break down rocks into sediment),
erosion (when soil and sediment is
moved from one place to another),
and deposition (the process in which
material is laid down).
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• Layers of sediment are pressed and cemented
together to form sedimentary rock. Most fossils
are found in sedimentary rock.
• Sandstone is an example of a sedimentary rock.
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Sedimentary Rocks form in
areas of deposition.
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See how individual pieces of sediment and
sand have stacked on top of each other and
pressed down so tightly it hardened into a
solid rock.
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Sedimentary Rock Animation
• Interactives . The Rock Cycle . How Rocks Change
Igneous Rocks
• Igneous rock forms when hot, liquid
rock, or magma, cools and solidifies.
(Magma is formed underground, but
it is called lava when it reaches the
surface.) Volcanos are associated
with igneous rocks.
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Intrusive vs. Extrusive Rock
• Intrusive igneous rock is formed beneath the
Earth’s surface. Because of the slow cooling
time, large crystals are formed.
• Extrusive igneous rock is formed on the Earth’s
surface, and since it cools quickly, very small or
no crystals are formed.
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Intrusive igneous rocks have
time to form large crystals.
Granite
An underground cave in Mexicomagma cooled very slowly- lots
of time for crystals to form.
Mount Rushmore is carved from granite in the Black Hills of South
Dakota.
Stone Mountain is made of Granite, an igneous rock.
Extrusive Igneous Rocks
Cool quickly on
the outside of the
volcano- little or
no crystals!
Animation of 2 Types of Igneous Rocks
• Interactives . The Rock Cycle . How Rocks Change
Metamorphic Rocks
• Metamorphic rocks are rocks in which
the structure, texture, or composition
have changed. Metamorphic rocks
are formed by extreme heat and
pressure.
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• Marble is an example of a
metamorphic rock.
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Animations
• Observe an animation of metamorphic rocks forming.
• Interactives . The Rock Cycle . How Rocks Change
Rock Cycle Rap and Song
http://www.youtube.com/watch?v=rkGVE6wNAzo
http://www.youtube.com/watch?v=lE3jR_RhxO4
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Rock Cycle Song
(Sing to the tune of "Row, Row, Row Your Boat")
SEDIMENTARY rock
Has been formed in layers
Often found near water sources
With fossils from decayers.
Then there's IGNEOUS rock
Here since Earth was born
Molten Lava, cooled and hardened
That's how it is formed.
These two types of rocks
Can also be transformed
With pressure, heat and chemicals
METAMORPHIC they'll become.
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“We Will Rock You”
http://www.youtube.com/watch?v=hAMBkoLhTBY
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Fossils
• Studying fossils helps us learn how the Earth’s
environment has been changed. In large
sections of sedimentary rock, the oldest fossils
will be found in the bottom layer.
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• Sometimes fossils from ocean animals are
found on tops of mountains! That means
that the mountain was once covered by
the ocean a very long time ago and the
mountain was raised up due to the
movement of lithospheric plates.
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Fossil Fuels
• Fossil fuels can be obtained by surface
mining, strip mining (removing long strips
of overlying soil and rock), and drilling
wells.
• The energy found in fossil fuels originally
came from the Sun.
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• Petroleum and natural gas form mainly
from decayed sea organisms.
• Smog is the photochemical base formed
when sunlight acts on industrial pollutants
and burning fuels.
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