Rocks are famous for staying put. If something is as “solid as a rock,” you assume that it’s
not going to change or go anywhere. However, in reality, rocks are always changing
and on the move. Nature’s constant recycling of them can be seen in mountains, rivers,
oceans, volcanoes, canyons, and earthquakes.
Rocks come in about one hundred varieties. There are also approximately 3,500
minerals, the stuff of which rocks are made. Together, rocks and minerals pave streets,
give color to paints, decorate jewelry, and put “lead” in pencils. Rocks are added to
food; iron is added to cereal for healthy blood and chalk is added to bread to make
our bones strong. We put rock salt on food for taste, and we also use salt to preserve
foods. Rocks are found in toothpastes and cosmetics. While rocks may not have
supernatural powers, as many once believed, they do have an influence on our lives.
Name ____________________________________
1
cleavage
the way some minerals break into smaller pieces with flat, shiny surfaces
crystals
minerals with a regular, repeating geometric shape
erosion
the transport of sediment; gravity is the driving force behind erosion, wind, moving water, glaciers,
and humans can also erode the Earth’s surface.
fossils
the remains or signs of past life often found within sedimentary rock
geologist
a scientist who studies rocks to learn about the Earth’s history and processes
gems
minerals that are cut and polished and often used to make jewelry
igneous rock
formed when hot, liquid matter (lava or magma) cools below or above the surface of the earth.
lava
hot, liquid magma (melted rock) that breaks to the surface of the Earth
luster
this physical property describes the rocks shininess - shiny, dull, glassy, and metallic
metamorphic
rock formed when extreme heat and pressure change existing rocks into other types of rocks –
shale changes to slate sandstone changes to quartzite
mineral
-a naturally occurring solid piece of matter that is not, and was never, alive
-the atoms of a mineral are arranged in a regular pattern to form crystals
-minerals can be rare gems: diamond, ruby, sapphire, and emerald
-are made of one element or a combination of elements
-metals: iron, gold, aluminum, copper, etc. are made of minerals
Mohs Scale
a scale developed to classify the relative hardness of minerals
opaque
not allowing light to pass through – a wooden door
rock
-a solid piece of matter made up of one or more minerals
-geologists classify them by how they were formed: igneous, sedimentary, metamorphic
rock cycle
the process through which one type of rock is changed, over time, into another type of rock
sedimentary
rock that forms when bits of sand, clay, and other sediments build up and cement
together under intense weight and pressure; fossils are commonly found in this rock
streak
the colored mark a mineral leaves when scratched across a surface
texture
how a rock feels – geologists use it to refer to the size of the pieces that make up the
rock: fine, coarse, granular, greasy
translucent
allowing light to pass through, but not able to see clearly – shear curtains, frosted glass
transparent
able to see through clearly – clear window glass
weathering
the process of wearing away by wind, movement of water, or glacial ice to break rocks into pieces
2
Inquiry Skills
Scientists use these skills to question, investigate and learn
Classifying
Arranging objects, events, or information according to some method
or system.
Geologists can group rocks by the way they were
formed: igneous, sedimentary, and metamorphic.
Generalizing
Drawing general conclusions from information.
All minerals are made from elements.
All rocks are made of combinations of minerals.
Making Decisions
Identifying alternatives and choosing a course of action.
When testing a rock or mineral for hardness, we will use our
fingernail first, then a penny, and then a steel nail. All three items
will scratch talc, so it’s important to start with your fingernail to
determine the hardness. Talc has a hardness of 1.
Manipulating
Materials
Handling or treating materials and equipment skillfully
and effectively.
When testing rocks and minerals for their hardness,
we used the following materials: rock and mineral samples, a penny,
a steel nail, and our fingernail.
Recording Data
Collecting information about objects and events.
We recorded our observations pertaining to the properties of the
rocks and minerals on our matrix sheet.
Inferring
Making a statement based on reasoning to explain an observation.
This rock is a sedimentary rock because it has a coarse sandy
texture and bits of seashell.
3
Earth is the third planet from the Sun. It is the only planet we know of that has just the right
environment for plants and animals to live on. Scientists believe Earth was formed about 4.6 billion years
ago. They think this happened when a force called gravity, an invisible pull that makes objects attract
other objects, pulled a cloud of gases and dust together. As the cloud spun around, small particles began
sticking together. Slowly planet Earth became denser and bigger. The heaviest materials, like iron and
nickel, sank to the center. At first Earth was very hot. As it cooled down it became hard on the outside.
Steam rose from the planet’s surface and fell back as rain. Over a long period of time, most of the Earth
became covered with oceans.
Earth has different layers. Earth’s crust, where you live, is made of a thick layer of rock, but it is
thin compared with the rest of the planet. The depth of the crust varies, but it averages about twenty-five
miles thick under the continents and about five miles thick under the oceans. If Earth were an apple, the
crust would be the thin apple skin. The crust includes the seven large landmasses called continents and
also the land under the oceans. The crust is made up of solid rock. All of the solid rock that covers Earth’s
surface is called the lithosphere. Above the Earth’s crust are mixtures of gases that make up the air you
breathe, mostly nitrogen and oxygen. The air surrounding Earth is called the atmosphere. Earth’s water:
rivers, oceans, glaciers, and lakes make up the hydrosphere.
Earth looks different on the inside. The inside of Earth is very hot. Heat and pressure melt some of
the rock under the crust. Heat and pressure also cause rocky materials inside Earth to move. These
movements cause changes in the crust.
The crust is not all in one piece. It is made up of giant pieces called plates. The plates float on
partly melted rock underneath the crust. This layer of the Earth is called the mantle. Most of the mantle is
made of hot, liquid rock called magma. Like oatmeal, magma is thick and it is constantly moving in giant
circles.
Imagine you are traveling from your home on Earth’s lithosphere to the center of the Earth. Your
trip will be about 4,000 miles long. As you travel, you pass through Earth’s four main layers: crust,
mantle, outer core, and inner core. The outer core is made up of very hot molten, melted, metals – iron
and nickel. It moves around the inner core very slowly, making electricity that many scientists believe
creates the Earth’s magnetic field. At the center of the Earth is the inner core, which is made of solid
nickel and iron with temperatures reaching 11,000ºF. That’s 50 times as hot as boiling water! It is thought
that the inner core is solid because of the huge weight of the rest of the Earth pressing all around it.
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Earth’s Structure
4
THE EARTH'S ATMOSPHERE
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The Earth's atmosphere is a thin layer of gases that surrounds the Earth. It’s composed of 78% nitrogen,
21% oxygen, 0.9% argon, 0.03% carbon dioxide, and trace amounts of other gases.
This thin gaseous layer:
 insulates the Earth from extreme temperatures
 acts like a blanket, keeps heat inside the atmosphere
 blocks much of the Sun's incoming ultraviolet radiation.
The Earth's atmosphere is about 300 miles thick. There is no exact place where the atmosphere ends; it
just gets thinner and thinner, until it merges with outer space.
The Layers of the Atmosphere:
Thermosphere. Temperature increases with
altitude.
•Mesosphere: Temperatures quickly
decrease as height increases.
•Stratosphere: 11 and 31 miles above the
earth's surface. The earth's ozone layer is
located in the stratosphere. Ozone, a form
of oxygen, is crucial to our survival; this
layer absorbs harmful ultraviolet solar energy.
•Troposphere: The troposphere is the lowest
region in the Earth's atmosphere. The
weather and clouds happen in the troposphere.
5
“Earth’s Heat “
By Joaquin Carr
Word Bank
mantle
convection
iron lava lithosphere
continental drift theory
earthquake
fault
nickel
crust
volcanoes
1. The ___________________________________________________is another word for the crust of
the Earth.
2. The idea that the Earth’s tectonic plates slowly shifted and caused the
land to separate into separate continents is known as the
_______________________________________________________________________
3. In the Earth’s _________________________________you will find hot molten
rock
This layer of the Earth is located beneath the lithosphere or crust.
4. _________________________________________ is the transfer of energy by the movement of a
liquid or gas.
5. A _________________________________ is a large crack in the Earth’s crust.
6. When magma breaks through the Earth’s surface it is known as ___________________.
7 - 8. The Earth’s inner and outer core is made up of mostly ______________ and _______________.
9. Earth’s plates are constantly moving. When the Earth’s crustal plates scrape against one another or
bump into each other an _________________________ may occur.
10. Earth’s plates are like pieces of a puzzle, they are huge pieces of _________________________.
11._______________________ often form when the oceanic crust slides beneath the continental crust.
12-14. The ___________________________, the _____________________________and
the _______________________________are the three main layers of the Earth.
6
The surface of Earth has mountains, valleys, rivers, and many other features. Mountains
rise up even from the bottom of the ocean. But long ago, Earth’s landforms, or surface features,
were different. How does Earth’s surface change over time? To understand how these land
formations were created; we must first look back more than 4.5 billion years to when the Earth
was mainly molten rock, magma. Over time, the surface of the Earth began to cool and harden
into the outer crust. Oceans were created as the low areas of the crust filled with rain, and the
parts of the crust that were not covered by oceans became the continents.
Over 300 million years ago, one huge land mass called Pangea existed, floating on the
Earth’s molten mantle. Pangea later broke into seven large landmasses called continents in an
ongoing process called continental drift. Continental drift is a theory that Earth’s crust is cracked
into sections called plates. The plates float on partly melted rock under the crust. The plates can
bump into each other, move apart, or slide past each other. Then people feel an earthquake, a
shaking of the ground. Strong earthquakes can destroy buildings, roads, and bridges. It is the
movement of these plates that helps change the land. Where plates move apart, the Earth
continues to experience volcanic activity, building underwater mountains. Where plates slide
under one another, deep trenches are formed as the crust is pushed into the mantle and is recycled
into magma.
The Earth’s most obvious land formations are its mountains. Volcanoes form mountains as
magma exits through the plate openings; it cools and builds upon itself. Many Pacific Islands, like
Hawaii, are Volcanic Mountains. The highest mountains form when two plates bump into each
other. The plates push against each other. This pressure squeezes the land and pushes it up. The
layers of rock form folds, or ripples in the crust. The Himalayan Mountains, including Mt.
Everest, are still rising because of this process. Sometimes movement of the plates causes a crack
in the crust. The crack is called a fault. Land on one side of the fault may get pushed up higher
than land on the other side. California’s Sierra Nevada Mountains were formed this way. Because
of Earth’s processes of weathering and erosion, older mountains are more worn and rounded than
newer mountains, which are usually sharper and taller.
Plains are vast low areas of flat land. They are formed by the rising of the bottoms of
shallow oceans or by the effects of weathering, erosion, and deposition, grinding down, carrying
away, and spreading out higher land formations.
Valleys are formed when rivers cut V-shaped channels down mountainsides. Over time,
these valleys widen due to weathering and erosion. Glaciers can also carve out huge valleys as
they move forward. Canyons, such as the Grand Canyon, are deep valleys created when a river
cuts through a high landscape called a plateau, leaving steep cliffs on either side. Over time,
weathering can change plateaus to mesas and buttes.
The weathering of ocean waves shapes shoreline land formations such as peninsulas and
bays. Land formations of the Earth are many and varied!
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Erosion
7
Earth’s Crust Rocks!
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Earth System: Plate Tectonics
Soon after the Earth formed, Earth’s rocky crust, the _______________________, hardened.
The crust is not one solid piece of rock; it is broken up into huge, thick pieces called
_______________. The Earth’s crust is broken into about thirteen major plates. The plates
drift atop the molten layer of the Earth called the _______________. The Atlantic Ocean gets
about 3 cm wider every year because of the movement of Earth’s plates. That is about as fast
as your fingernails grow. Around 1912, a geologist named Alfred Wegener hypothesized that
200 million years ago all the continents were joined into one super continent. He called this
great landmass __________________, which means “all Earth.” The fossil record supports
and gives credibility to the theories of continental drift and plate tectonics. A fossil called
Mesosaurus has been found in both South America and Africa.
1. What feature of the continents best suggests that they were once joined?
a. Some continents fit together like puzzle parts.
b. Some continents are the same size.
c. All continents have mountain ranges.
d. All continents contain the same fossils.
2. The Earth’s crustal plates move on the
a. lithosphere
b. mantle
c. outer core
d. inner core
3. The Earth creates new crust by ___
a. magma from the mantle
b. nickel and iron from the core
8
All About Plate Tectonics:
Earth's Plates and Continental Drift
The Earth's rocky outer crust solidified billions of years ago, soon
after the Earth formed. This crust is not a solid shell; it is broken up
into huge, thick plates that drift atop the soft, underlying mantle.
The plates are made of rock and drift all over the globe; they
move both horizontally (sideways) and vertically (up and down).
Over long periods of time, the plates also change in size as their
margins are added to, crushed together, or pushed back into the
Earth's mantle. These plates are from 50 to 250 miles (80 to 400
km) thick.
The map of the Earth is always changing; not only are the plates moving, but the plates change
in size. Also, the sea level changes over time as the temperature on Earth varies and the poles
melt or freeze, covering or exposing different amounts of crust.
What is Pangaea? In 1915,
the German geologist and
meteorologist Alfred Wegener
(1880-1930) first proposed the
theory of continental drift,
which states that parts of the
Earth's crust slowly drift or move.
The fossil record supports and
gives evidence to the theories
of continental drift and plate
tectonics.
Wegener hypothesized that there was an original, gigantic supercontinent 200 million years
ago, which he named Pangaea, meaning "All-earth". Pangaea was a supercontinent consisting
of all of Earth's landmasses.
9
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Earth System: Types of Rocks
Earth’s surface, where you live, is made of a very thin layer of rock. Earth’s rocky surface
is called the lithosphere. Above the Earth’s surface is a mixture of gases that make up the air you
breathe. The air surrounding Earth is called the atmosphere. The gas that makes up most of
Earth’s atmosphere is nitrogen. Oxygen is second. All the other gases add up to only 1%. Earth’s
water makes up the hydrosphere. The hydrosphere includes all the liquid water and ice on Earth’s
surface, liquid water in the ground, and water vapor in the atmosphere. The lithosphere,
atmosphere, and hydrosphere interact with each other. For example, water evaporates from a lake
and enters the atmosphere. Some of this water falls back to Earth as rain. The rain fills streams
and rivers. Moving water, weathering, wears away Earth’s rocky surface.
We live on Earth’s surface; it’s called the crust. Under the soil, the crust is made up of
layers of rock. Parts of these layers have been brought to the Earth’s surface by glaciers,
earthquakes, volcanoes, and mining. Most of the Earth’s rock crust is still covered by soil or
water.
When the Earth first formed, all rocks came from hot melted rock that cooled and became
solid. The molten rock is called magma. The magma cools and solidifies. Rocks that formed this
way are called igneous from the Latin word for fire. There are many different kinds of igneous
rocks because of the many combinations of elements that form them.
The kind of igneous rock formed also depends on factors like temperature and speed of
cooling. When magma cools very slowly under the surface of the Earth, it forms “intrusive”
igneous rock. Granite is an example of an intrusive rock. The hot molten rock, which formed
granite, cooled so slowly that the minerals in it separated from one another and formed crystals.
That is why there are many colors in granite. Magma, which reaches the surface through
volcanoes, is called lava. It cools quickly and forms “extrusive” igneous rock. Obsidian and
pumice are examples of extrusive igneous rock.
Over millions of years, wind, moving water, and glaciers wear Earth’s rocky crust down.
When the sediments – sand, mud, clay, and the remains of plants and animals - settle to the
bottom of a river or sea, we say that they are deposited. The deposited rocks build up in layers
over a long period of time. The weight of the sediments on top squashes the sediments at the
bottom. The water is squeezed out from between the pieces of rock and crystals form. The
crystals or minerals help cement the sediments together. The processes of weathering (wearing
down the rock), erosion (moving of sediments and rocks), depositing, and cementing of materials
can form sedimentary rocks such as limestone, shale, and sandstone.
Metamorphic means to “change form.” Metamorphic rocks are igneous, sedimentary, or
metamorphic rocks that have been changed by heat and pressure deep inside the Earth. Earth
movements may cause rocks to be deeply buried or squeezed. As a result, the rocks are heated
and put under great pressure. They do not melt, but the minerals they contain are changed
chemically, forming metamorphic rocks. Sometimes metamorphic rocks form when rocks are
close to some molten magma and they get heated up. Limestone can change to the metamorphic
rock marble. Shale can change to slate and sandstone can change to quartzite.
10
Rocks Earth Science in Action
1. The solid materials that form the Earth’s crust or lithosphere, both on land and at the bottom of the
oceans are called _______________________.
2. ______________________________ form the deserts, mountains, and beaches.
3. They are a mixture of minerals: ___________________________________
4. Rocks are continuously being formed as a result of weathering, erosion, volcanic action, or heat and
pressure deep within the Earth. This is called the _________________________________________
5. ________________________________ rocks start out as magma or lava.
6. This igneous rock forms when magma exits, then cools and hardens on the Earth’s surface:
______________________________ (intrusive or extrusive)
7. Igneous rock that cools and hardens below the Earth’s surface: _______________________________
8. The molten rock found beneath the Earth’s surface is called: _____________________________
9. When magma is above the Earth’s surface it is called____________________________
10. __________________________________ rocks are formed by the compacting of layers of sediments.
11. Sediments are small pieces of: _________________
_________________
__________________
12. Extreme ____________________ & ________________________ and chemical action deep inside
the Earth change rocks into new rocks. Ex. Limestone changes to marble
Shale changes to slate
11
Rocks and Minerals
Mini-book
1. Rocks are made of one or combinations of ___________________________.
2. Igneous rocks, “fire rocks,” form from cooled ____________________ or
_____________________.
3. Layer upon layer of sediments pile on top of each other to form
________________________________ rock.
4. The remains or signs of past life can often be found in sedimentary rocks, these clues
to Earth’s past are called _________________________________.
5. Earth’s extreme heat and pressure can change an igneous, sedimentary, or a
metamorphic rock into a new rock, these rocks are called ________________________
rocks.
6. Look at the diagram on page 17 of the Rock Cycle.
What processes form igneous rocks? ______________________________________
What processes form metamorphic rocks? __________________________________
What processes form sedimentary rocks? ___________________________________
7. What physical property describes a rocks true color? ________________________
8. A fingernail, a penny, a steel nail, or a diamond is used to scratch a rock or mineral to
find this property: _____________________________
9. Gems and metals are __________________________________.
12
Earth’s land is always changing. The Earth’s plates can move and bump into each other
to form mountains or create a volcano. Processes on Earth’s surface cause other
changes. Right this minute, wind and water are working together to wear down the
land in some places and build it up in others. Wind and water work slowly, but, they can
cause big changes over long periods of time.
Weathering
As you have learned, Earth’s land surface is made up mostly rock. Rock is hard, but
wind and water can slowly break rock apart. The breaking down of rock on Earth’s
surface into smaller pieces is called weathering.
Wind and water can carry sand and other small pieces of rock. You know that you can
smooth a piece of wood with sandpaper. Blowing sand acts like sandpaper. It scrapes
and wears away the surface of rock. Sand and pebbles carried by moving water also
weather rock. On rocky coasts, ocean waves break down rock cliffs in this way.
Rain causes weathering, too. Rainwater can seep into cracks in rock. If the temperature
gets cold enough, the water freezes. When water freezes, it expands, or takes up more
space. The ice in the cracks pushes against the rock. Over time, repeated freezing and
thawing of water may split rock apart.
Plants also cause weathering. The roots of plants can grow into cracks in rock. As the
roots become larger, they break the rock into smaller pieces.
Wind, water, and sometimes plants work together to weather rock. Weathering usually
makes rock smoother. Over thousands of years, weathering can shape rock into
different formations like arches, canyons, and columns.
Weathering over long periods of time breaks rock into smaller and smaller pieces. These
pieces include pebbles, sand, and even smaller bits of rock. All of these loose pieces of
weathered rock are called sediment. By creating sediment, weathering helps form soil.
Soil is the material in which most plants grow. Soil is made up of sediment, the remains
of living things, air, and water.
13
Erosion and Deposition
Some sediment stays in place, but much of it gets moved away. The process by which
weathered rock is picked up and moved to a new place is called erosion. If you have
been in a sandy place on a windy day, you know that wind picks up sand and moves it.
Strong winds can bounce and roll larger pieces of weathered rock along the ground.
Flowing rivers pick up sand and pebbles from the riverbanks and river bottoms. Rivers
may carry this material a long distance. Ocean waves also pick up and move sand and
other pieces of weathered rock.
Glaciers are huge sheets of ice that move slowly over land. As glaciers move, they pick
up pieces of rock. A glacier can carry boulders the size of cars.
Erosion would not happen without gravity. On Earth, the force of gravity pulls everything
down toward the center of the planet. Gravity makes water flow and winds blow.
Sometimes gravity causes erosion directly, by pulling pieces of rock downhill. The
sudden movement of rocks and soil down the side of a hill is called a landslide.
Gravity also causes deposition, the process by which eroded sediment is dropped in a
new place. When wind and water slow down or stop, the sediment they were carrying
falls to the ground. Glaciers also leave rock behind. Deposited sediment builds up the
land, often far away from the places where the sediment formed.
1. Which one is a definition of weathering?
a. the movement of rock pieces from one place to another
b. the breaking down of rock into smaller pieces
c. the building up of land
d. a force that pulls pieces of rock downhill
2. Which word names the process of picking up and moving weathered rock?
a. deposition
b. landslide
c. erosion
d. weathering
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Earth System: Erosion
14
Weathering and Erosion
Video
1. Name a landform: ____________________________________________________
2. The thinnest layer of the Earth is called: ___________________________________
3. The wearing down and breaking rocks into pieces is called: ______________________
4. What causes weathering, breaking rocks into smaller pieces?
a. __________________________________
b. __________________________________
c. __________________________________
d. __________________________________
5. Small pieces of rock, sand, soil, and seashells are called: ______________________
6. When water freezes it ____________________________ or gets bigger.
7. The picking up and carrying away of weathered rock pieces is called: ______________
8. What causes erosion?
a. ______________________________________
b. ______________________________________
c. ______________________________________
d. ______________________________________
e. ______________________________________
9. The force that pulls everything toward the center of the Earth is called: _______________
10. ________________________________ & _______________________________ are constantly
changing the surface of the Earth.
15
Weathering & Erosion
Rocks and other materials on the Earth’s surface are constantly subjected to the powerful forces of
weathering, erosion and deposition. Weathering is the breakdown of rock and other materials into smaller
pieces. Rocks can be broken down by physical or chemical weathering. Physical weathering is the
cracking, breaking up and grinding down of rocks into smaller pieces while maintaining the same mineral
composition. Changing temperatures cause rocks to crack and flake, ice splits rocks open, living things
dig or pry open rocks, gravity causes rocks to fall and shatter, and rubbing, abrasion, breaks down rocks
with solid particles like sand.
Erosion is the process through which weathered rock is moved from one place to another place.
Land can be eroded in one of five ways – by gravity, glaciers, running water, waves, or wind. When rocks
and soil on a slope are loosened, gravity pulls them downward.
A glacier is a large mass of slowly flowing ice. Glaciers form in cold areas where snow piles up
and freezes. Water freezes in cracks in the rock underneath the snow and weathers the rock. As the glacier
moves, it carries away weathered pieces of rock.
Wind can wear away at rocks, smoothing them out. Wind also can move sand or sediment from
one place to another. When the winds slow down, the sand and soil are deposited.
Waves often either hit beaches at an angle or curve as they move into shallower water. This means
that as they erode the shoreline, they move sand and rocks further down the beach or to the side. When
waves wash sand off beaches, the sand may be deposited in the water rather than back on the beach. Over
time, enough sand has been deposited in the water that a strip of sandy land forms. This strip of land is
called a sandbar. A sandbar may last for some time until movements of ocean water break it down.
1. The breaking down of rock on Earth’s surface into smaller pieces. ________________________
2. The moving pieces or rock from one place to another is called __________________________.
3. ______________________________ breaks off pieces of rock; _________________________
carries those pieces away.
4. What might move the broken pieces, sediments, of rock to another location? ________________
________________________________________________________________________________
16
Rocks and Minerals Review
Write Rock, Mineral, or Both.
1. _______________
Formed by Earth’s natural forces, nature, in or on the Earth’s crust.
2. _______________
Made of one or more elements or chemicals.
3. _______________
Can be a rare gem like a diamond or a ruby.
4. _______________
Metals: iron, aluminum, gold, lead, silver, copper, etc.
5. _______________
May contain fossilized remains of plants or animals.
6. _______________
It is made of one or more minerals.
7. _______________
Geologists classify or group them by how they were formed: igneous, sedimentary,
or metamorphic.
8. ______________
They are found on the Earth’s thin rocky crust.
cleavage
rocks
geologist
sedimentary
hardness
streak
igneous
texture
luster
translucent
opaque
transparent
9. This test is performed to identify a mineral’s true color. ____________________________
10. Geologists record if a rock or mineral reflects the light. They use the term ___________________________.
11. If you are able to look through a rock and see details of an object behind it, it is _______________________.
12. If light will go through it, but you wouldn’t be able to see through it clearly, it is _____________________.
13. If the rock sample does not allow light to pass through it, it is __________________________.
14. Geologists use the word __________________ to describe the size of the pieces that make up a rock or mineral.
15. A geologist would use the ____________________ test to test a rock for its resistance to scratching.
16. Some minerals will naturally break, showing flat, shiny surfaces. This is called ________________________
17. They are made of mixtures of minerals, and they are found on the Earth’s crust. _______________________
18. A scientist who studies the history of the Earth, rocks, and uses of rocks is called a
_______________________
19. These rocks form from cooled magma or lava. ________________________
20. These rocks form layers of sediments; fossils can be found in this kind of rock. __________________
17
Identifying Rocks and Minerals
Geologists study rocks to provide information about the history of the Earth. Some
geologists determine the age of rocks and identify different types of rocks and minerals.
Others work to find new uses for rocks and minerals. Many geologists study rocks to
search for new sources of minerals and other valuable materials such as oil or natural
gas.
Rocks come in many different shapes, sizes, and colors. Some rocks are flat and
smooth. Other rocks are sharp and have bumps on them. Some are glassy, while others
look dull. You might find white, green, brown, or pink rocks. What are rocks made of?
What gives them their qualities? What makes rocks different from each other?
A mineral is a nonliving material found in Earth’s crust. About 4,000 different
minerals are found naturally on Earth. Each mineral has its own traits, or properties. A
property is something you can observe, such as color or shape.
All rock is made up of minerals. Only a few of Earth’s many minerals make up
most of its rock. Some kinds of rock are made up of one mineral. Others contain two or
more minerals.
Common Minerals
You are likely to have some very common minerals right in your house. Table salt is
a mineral called halite. We use it to put flavor in our food. Gold and silver are minerals.
We use gold and silver to make jewelry.
Metals like copper and iron come from rocks, too. Electric wires are made of
copper. So are some pipes. Iron is in many objects, from pots and pans to airplanes.
Many buildings and statues are made of rock such as marble, limestone, or granite.
Each kind of rock is always made up of the same kinds of minerals. For example,
granite is always made of quartz and feldspar. The chart below shows the minerals that
make up some of the different types of rock.
http://www.brainpop.com/science/earthsystem/
Earth System: Mineral Identification
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Properties of Rocks and Minerals
Scientists identify minerals by looking at their properties. These properties include texture,
luster, hardness, color, magnetism, acid, and conductivity. You cannot identify a rock or
mineral if you know only one property. Two minerals may have the same color or luster.
But no two minerals share all the same properties.
Did you know? Pyrite is sometimes called “fool’s
gold.” Its luster and texture are very similar to those
of gold. But you can tell the minerals apart by their
streak. Gold leaves a yellowish streak. Pyrite leaves
a streak that is blackish-green.
Luster – Different minerals reflect light in different ways. The way a mineral reflects
light is called its luster. Some minerals have a metallic luster. They shine like metals. Other
minerals do not look shiny. They look dull. Gold has a metallic luster. Quartz does not.
Color – Color can also help identify minerals. Each mineral is found in certain colors.
Suppose scientists have an unknown white mineral. It could be calcite because calcite
is white. It is not obsidian, since obsidian is black. Some minerals are found in many
colors. Quartz can be pink, white, purple, yellow, brown, or black.
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Hardness Test Hardness is the resistance of a rock to being scratched. Only minerals
have a consistent hardness because they are chemically the same. The hardness of
rocks such as sandstone can vary from soft to hard depending on the mix of minerals in
different samples.
Mohs scale of hardness can be used to help identify minerals. Mohs scale ranks minerals
from 1, soft, to 10, hard. Mohs scale lists ten sample minerals and their hardness.
A diamond is the hardest mineral and has a hardness of ten. There are no diamonds in
the Rocks and Minerals kit.
Did you know?
The only type of rock that will float in water is a
type of igneous rock called pumice.
Magnet Test
This test is performed to identify rocks and minerals that contain large
amounts of iron. One mineral in the kit is magnetite. If the sample of magnetite is pure
enough, it may be magnetic enough to pick up a small paper clip.
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Streak – A mineral also leaves a color when it is
rubbed against a special plate. The color the
mineral leaves on the plate is called its streak. A
mineral’s streak may be different from its color.
Many minerals change color on the surface
where they were in contact with air and water.
For example, pyrite’s color is yellow, but it leaves
a green-black streak.
As you remember, conductors allow
electrons to flow through them; all metals
conduct electricity. Conductivity means
how well electricity flows through a
substance.
Acid Test Some rocks and minerals contain carbonates.
A weak acid can be used to test for these chemicals in a rock
and mineral. Acid will react with the carbonate to make
carbon dioxide gas that can be seen as bubbles.
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Eyewitness Rocks and Minerals video
erosion
mining
fossil
outer core
geologist
hydro
paleontologist rock cycle
inner core
sediments
lava
lithosphere
solidify weathering
magma
mantle
1. Layers of sedimentary rock can be changed into metamorphic rock. These and other rocks may be reheated and
changed to molten rock (magma), which may become igneous rock again. Rocks are continuously being formed
and changed by Earth’s processes. ________________________________________
2. To make or become solid, compact, or hard. _____________________________
3. A scientist who traces life in the past, excavates, and studies fossils. _____________________________
4. A scientist who studies the history of the earth, especially as recorded in rocks. _______________________
5. The layer of the earth that consists of hot, solid metals – nickel and iron. __________________________
6. The relatively thin rocky layer of the earth. ______________________________
7. The remains or trace of a plant or animal from a past age, preserved in the earth’s sedimentary rock
______________________________
8. This prefix means water. ____________________ (Earth’s hydrosphere: lakes, rivers, glaciers, oceans)
9. Hot molten (melted) rock, which makes up the Earth’s lower mantle. __________________________
10. Magma that has reached the surface or crust of the earth. _____________________________
11. The mostly molten rock layer of the earth. _______________________________
12. Digging a pit or tunnel in the earth to obtain mineral substances. _____________________________
13. This layer of the earth is made of molten metals – nickel and iron. _____________________________
14. When chemical and physical forces (wind, moving water – rivers/waves) wear down or break rock into pieces,
changing their shape and appearance. ___________________________________
15. Materials such as stones, sand, shells, and clay; these are deposited, layer-by-layer, by water, wind, or glaciers
to make sedimentary rock. _________________________________
16. Gravity, wind, water, and glaciers can transport, move, sediments from one place to another._______________
Geologists can classify, group, rocks into three categories based on how they were formed by the earth.
igneous rock
metamorphic rock
sedimentary rock
17. __________________________ Rock that has been changed within the earth; this usually occurs through great
heat and pressure.
18. Rocks formed from the cooling of molten rocks underneath the earth’s crust and on the earth’s surface.
________________________________
19. Rocks that are formed from layer upon layer of sediments usually deposited at the bottom of seas and lakes.
These rocks usually contain fossils. _____________________________________
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Classifying Rocks
Scientists classify or group rocks by how they were formed. Scientists put all rocks into three big groups:
igneous rock, sedimentary rock, and metamorphic rock.
Igneous rock starts as melted rock under Earth’s crust. This melted rock is called magma.
Sometimes magma reaches Earth’s surface, such as through a volcano. Then the melted rock is called
lava. When magma or lava cools, it becomes solid and forms igneous rock. Granite is one kind of
igneous rock that forms from magma. Basalt is a kind of igneous rock that forms from lava.
Sedimentary rock forms in flat layers over a long period of time. You learned that weathering
breaks down rock on Earth’s surface into smaller pieces. These loose pieces of rock are called
sediment. Some sediment settles in layers on the bottoms of rivers, lakes, and oceans. As the layers
build up, pressure builds up, too. The heavy weight or pressure of the top layers squeezes the layers
together. After a very long time, the layers of sediment stick together and form sedimentary rock.
Sedimentary rocks usually contain fossils, the imprint, of a plant of animal that was preserved between
the layers of sediments. Sandstone is a common kind of sedimentary rock.
Sometimes surface rock gets pushed deep inside Earth. There, heat and pressure cause chemical
changes in the rock. This process forms metamorphic rock. Both igneous and sedimentary rock can be
changed into metamorphic rock. Metamorphic rock can be changed into a different kind of metamorphic
rock. Shale, a sedimentary rock, can be chemically changed, by heat and pressure inside the Earth, into
a metamorphic rock called slate.
The Rock Cycle
Earth’s rock is always changing. It is being formed and broken down. On Earth’s surface, wind, water,
and gravity change rock. Inside Earth, heat and pressure cause changes. Each of the three types of rock
can turn into one of the other types. All of the types of rock can also melt and become magma. All the
changes of rock from one type to another are called the rock cycle. Follow the arrows in the diagram
below to see how each kind of rock can change.
http://www.brainpop.com/science/earthsystem/
Earth System: Rock Cycle
23
http://www.brainpop.com/science/diversityoflife/
The history of the Earth is recorded in its rock layers. The age of the rocks, as well as their
placement in relationship to one another, tells a story. The story is a history of the Earth.
Rock layers are laid down one on top of another. The newer the rock layer, the closer it is to the
surface, unless something happens to move, bend, or fold the layer. The fossils in the layers can
also determine the age of rock.
The only direct way we have of learning about dinosaurs
is by studying fossils. A fossil is
the preserved trace or remains of a once-living thing. A flat fossil of an organism or the trace of
an organism that was originally made in soft soil or mud is called an imprint. A mold is a type of
fossil that formed when an animal died and then it was covered with mud that hardened. The
organism dissolved, leaving the space inside. Fossils have been found on every continent on
Earth, maybe even near where you live. The word fossil comes from the Latin word fossilis,
which means "dug up."
Most fossils are excavated
from sedimentary rock layers
. Sedimentary rock is rock
that has formed from sediment, like sand, mud, small pieces of rocks. Over long periods of time,
these small pieces are compressed (squeezed) as they are buried under more and more layers of
sediment that piles up on top of it. Eventually, they are compressed into sedimentary rock. The
layers that are farther down in the Earth are older than the top layers.
The fossil of a bone
doesn't have any bone in it! A fossilized object has the same
shape as the original object, but is chemically more like a rock. Paleontology is the branch of
biology that studies the forms of life that existed in former geologic periods, chiefly by studying
fossils.
The cross section below shows fossils and the rock layers in which they are found. Crustal
movement has not moved the rock layers.
Which fossil is considered the oldest in the cross section shown above?
a. armored fish
b. dinosaurs
c. early horses
d. trilobites
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The Rock Cycle
The Earth is active and the Earth’s surface can change very quickly
Volcanoes are erupting and earthquakes are shaking
Mountains are being pushed up and are being worn down
Rivers are carrying sand and mud to the sea
Huge slabs of the Earth’s surface called plates are slowly moving about as fast as your fingernails grow
1. What type of rock forms directly from magma? _______________________________
2. Identify two processes most directly involved in the formation of igneous rock.
(1) _____________________________________________
(2) _____________________________________________
3. Identify three processes required for the formation of a sedimentary rock.
(1) ______________________________________________
(2) ______________________________________________
(3) ______________________________________________
4. Name one process involved in the formation of metamorphic rock.
(1) ______________________________________________
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Have the students create an illustration to show an ecosystem that includes the atmosphere,
hydrosphere (lake, river, ocean, pond, rain, clouds), lithosphere, and biosphere (living things –
plants and animals). www.brainpop.com (ecosystems)
Ideas:
beach – swimming, fishing, boating, building sand castles
mountains – hiking, skiing, mountain lake
– The gases, mostly
nitrogen and oxygen, which surround planet
Earth.
Atmosphere
Hydrosphere – All the water on Earth and in
its atmosphere: oceans, lakes, glaciers, ground
water, water vapor, and clouds.
Biosphere – All the living things on
Earth - plants and animals.
Lithosphere –The solid, rocky surface of the
Earth. The part that our schools, homes, and stores
are built on.
Atmosphere – The gases, mostly
nitrogen and oxygen, which surround planet
Earth.
Hydrosphere – All the water on Earth and in its
atmosphere: oceans, lakes, glaciers, ground water,
water vapor, and clouds.
Biosphere – All the living things on
Earth - plants and animals.
Lithosphere –The solid, rocky surface of the
Earth. The part that our schools, homes, and stores
are built on.
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Video: Rockfinders - Learn About Rocks and Minerals with Max Orbit
1. New _________________ are being formed, reshaped, and transformed everyday.
2. Steel, concrete, and glass are materials made from __________________.
3. Rocks are made of one or more __________________________________.
4. Salt, diamonds, silver, and gold are ___________________________________.
5. A quarry is where people mine ___________________________________.
6. _________________________ are solid matter found in nature.
7. ___________________________ are the basic building blocks of the Earth’s crust.
8. There are over 3000 different types of _________________________________.
9. The Earth’s top layer is called the _____________________________________.
10. The partly molten layer of rock beneath the crust is called the _____________________________
11. The layer under the mantle is called the ______________________ and it is made of hot, liquid
metals.
12. The inner core is made of solid _______________________& _________________________.
13. ______________________________ rocks are formed from magma or lava.
14. _________________________________ rocks are formed from layers of sediments pressed to form
rock.
15. _________________________________ rocks are created when heat and pressure combine to change
existing rock into another type of rock.
16. __________________________ is the process of breaking down and wearing away rocks. The Grand
Canyon is a good example of weathering caused by water.
17. Weathering is caused by ________________, __________________ and ______________________.
18. Weathered rock is picked up and transported to a new place. ________________________________
17. Erosion is caused by _______________________________________________________________.
20. All the changes of rock from one type to another, the ___________________________________
illustrates how rocks are formed and reformed over and over again.
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Rock BINGO
Write each word neatly in a box, you also have a free space.
conductivity
hardness test
mantle
rock cycle
gems
igneous rock
metamorphic rock
streak
earthquake
inner core
minerals
sedimentary rock
erosion
hydrosphere
outer core
sediments
fossil
lithosphere
plates
volcano
gravity
magma
rocks
weathering
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