Download Rocks and Minerals Lesson 5

BIG IDEA:
Rocks and minerals have properties
that can be: observed, tested,
described, identified and recorded.
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What does the object look like?
Where have you seen it before?
What is it used for?
What do you think it is?
The Geologist thinks we are ready to start identifying the
rocks in the collection and believes some of the ingredients
that make up the rocks look like minerals we have already
identified. Remember, rocks are different than minerals
because they are often a combination of minerals and other
materials. He recommends that we start with investigating
the rocks we made in class. The geologist would like us to
prepare a report of the minerals found in the rocks we
created and describe the properties we observe. To assist
in our rock investigation he has sent some information and
materials that will help us dissect the rocks and further
identify their materials.”
What does the geologist want us to do?
What did the geologist give us to help?
What is the problem we need to solve?
How can we…
I think that we can…because…
Before we begin our investigation, and test our
predictions, lets review how rocks are formed and the
processes we used to create our own rocks.
 What are the three main earth processes in which
rocks are formed?
igneous, metamorphic, and sedimentary
 How is the process by which you formed your rock
different from how rocks are formed in nature?
 Our rocks were formed in a matter of weeks. In
nature this often takes thousands of years and
extreme pressure or heat.
Conglomerate
A rock made of mineral and rock fragments held together in clay
or another cementing material.
Breccia
A sedimentary rock composed of angular mineral and rock
fragments held together in clay or another cementing material.
Before we begin dissecting our rocks I would like you to
review and create a checklist of the ingredients you used to
make your rocks in your scientist notebook.
Rock Materials:
 Alum
 Clay
 Gravel
 Salt
 Sand
 Talc
 Water
 3 mystery minerals
 An item to fossilize
When we dissect our rocks I would
like you to keep track of each
ingredient you can find and identify.
Record and draw examples of any
interesting observations you find in
your science notebook.
For example: If you have a fossil
imprint what does it look like?
1.
2.
3.
4.
Use a nail to carefully pry apart and dissect your
rock
Sort the larger solid pieces to one side (gravel,
sand, mystery materials)
Put the powder residue and small particles into a
vial
Identify each mystery mineral using your mineral
tests
Mystery Mineral
Luster
Hardness
Streak
Acid Test
What are the mystery minerals found in your rocks?
How were you able to identify them… What’s your
Evidence?
Which Rock Ingredients Have You Found so Far?
Rock Ingredients:
Alum
Clay
Gravel
Salt
Sand
Talc
Water
3 mystery minerals
An item to fossilize
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After you have placed the powder residue into your
vial, add some sand and other small solid materials.
The vial should be about ½ full.
Fill the remainder of the vial ¾ full of water.
Cap the vial and shake vigorously.
Place the vial in a location that it will not be disturbed
until our next meeting.
Quick Write:
We know that sedimentary rocks are formed from layers of
material that have settled and become compacted or
cemented together. What will your vial look like after the
materials settle? How will the small pieces of gravel, sand,
clay, or talc settle and distribute themselves?
Be extremely careful to not disturb your sediments in the vial!
We recently identified the 3 mystery materials in the rocks
we formed and set a solution of sediments from those rocks
aside to see how they would settle.
Which particles settled to the bottom first and which
particles settled toward the top?
 Larger pieces (gravel and sand) are on the bottom while
smaller pieces (clay and talc) are on the top.
Why does this happen?
 The size and density of the particles determines which will
settle first. Layers of sediment in sedimentary rocks are
also deposited in this way.
Why do you think I asked you to shake the vials of sediment
and water?
Do you think this may have caused some of the materials to
dissolve in the water?
 Some of the particles will dissolve in water.
What have we previously learned from our geologist about
materials that dissolve in water?
 If the liquid evaporates the particles could be crystallized
and identified.
How can we…
How can we identify the materials that have dissolved
in the solution of water?
I think that we can…because…
Hint: Which rock ingredients from your list are still missing?
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Carefully pour just the liquid from your vial into an
evaporation tray.
Place the tray in a warm, ventilated area so the water
can evaporate.
Quick Write:
What do you think you will find when all the water
evaporates?
Using your magnifying glasses, I want you to examine and record
your observations in your scientist notebook.
Evaporated Solution
Number of Days to Evaporate:
Picture
Description
Now that your liquid solutions have evaporated, were you able
to observe crystals that formed?
What is the shape of the crystals?
Based on the materials that we used to form our rocks
(Gravel, sand, salt, clay, and talc) discuss with your group and
try to identify the cubic-shaped crystals you see in your tray?
Be ready to provide evidence that will support your opinions.
Identify the type of crystals you drew today in your scientist
notebook and explain why they are in fact salt crystals.
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What is the difference between a rock and a mineral?
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What minerals were present in your rocks? How do you
know for sure?
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Quartz, pyrite, calcite
Why does sediment from rocks settle in layers?
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Minerals are one solid material
Rocks are made of several materials
The materials settle based on their density. Heavier materials
sink/settle faster while lighter materials settle slower.
Why were the crystals that formed from our evaporated
solution cubic?
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Salt was an ingredient in our rocks that dissolved in the water
we added to the vial. Salt will always have cubic crystals no
matter were they are found and how they are formed.
Based on what you have learned from your investigation
of crystals, you need to record at least 3 claims and
evidence statements in your science notebook.
I claim that…
I know this because…
Possible Examples:
I claim that our rocks contained pyrite, calcite, and
quartz. I know this because…
I claim that the crystals that formed from our solution
were salt crystals. I know this because…
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What did you learn…?
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What really surprised you…?
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What new questions do you have…?
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What would you like to know more about…?