Senior High School

Earth Science
Quarter 1 - Module 2

Classification of Rocks
Important Minerals to Society

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 What I Need to Know

This module is designed to help you master the classification of rocks.

After going through this module, you are expected to:

1. classify igneous, sedimentary, and metamorphic rocks; (S11ES-Ic-6)

2. identify the characteristics of igneous, sedimentary and metamorphic rocks.

Earth Science
The Classification of Rocks
Lesson 1

This lesson will explore the different types of rocks existing in our environment. The learner is
expected to identify and classify rocks into igneous, sedimentary, and metamorphic.

What’s In

In the previous module, you have learned the common naturally occurring minerals such as
feldspar, quarts, mica and alike. Those minerals are called rock-forming minerals because they are the
building blocks of rocks. For example, when quarts, feldspar and mica come together, they form a certain
type of rock. Different combinations of minerals form different types of rock. In this lesson, you will learn
how rocks are grouped or classified with their distinguishing characteristics.

What’s New

Directions: Collect 10 rock samples from your garden or yard. Using magnifying glass, observe the
rocks. Create a grouping of the rocks based on your observation. Label your rock samples as sample 1
to 10. As proof, take pictures.

Guide Questions:
1. How many groups did you form from your collected samples of rocks?
2. What basis of grouping or classification did you use?
3. Can you describe the common features of each group?

What is It

How can we classify rocks? Would it be by color, hardness, texture, density or other physical
properties? Is it by chemical composition? You may have a little knowledge that rocks can be Igneous,
Sedimentary or Metamorphic. But how did geologists come into these three classifications? What do
you think was their basis for classification? Rock is a naturally occurring solid aggregate of minerals
sometime with non-mineral solid particles.

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Classification of Rocks
Igneous rocks or magmatic rocks are formed through the cooling and solidification of magma or
lava. Igneous rock can be classified into:

Intrusive igneous rocks. This type of igneous rock is

formed from solidification of magma below the surface.
They have large crystals of minerals that formed overtime
through slow process of crystallization in a magma.
Granite, diorite, gabbro, pegmatite, and peridotite are
example of this type of rock.

Extrusive igneous rocks. This type of igneous rock is

formed through faster rate of solidification of lava on the
surface of Earth. They can become glassy in appearance
due to less crystallization or vesicular like Scoria, due to
the air that was trapped inside when they solidified and
formed on the surface of the earth. Other examples of this
type of rock are andesite, basalt, dacite, obsidian, pumice,
rhyolite and tuff.

Sedimentary rock is formed by the deposition and

cementation of mineral or organic particles on the floor of
oceans and other bodies of water at the Earth surface.
Sedimentary rocks can be classified into clastic, chemical
and organic.

Clastic sedimentary rock. It is formed from the mechanical weathering debris of rocks.
Examples are breccia, conglomerate, sandstone, siltstone, and shale.
Chemical sedimentary rock. It is formed when dissolved materials precipitate from solution.
Examples of these are rock salt, iron ore, chert, flint, some dolomites.
Organic sedimentary rock. Formed from the build-up of plant or animal debris.

Metamorphic rock forms from existing rock types called

“parent rock” in the process called metamorphism, which
means change in form. The original rock which can be an
igneous, sedimentary or another metamorphic rock is
subjected to heat and pressure, causing a profound
chemical or physical change. Metamorphic rocks can be
further classified into:

Marble
Foliated metamorphic rocks. Formed through pressure due to compression of rocks that create bands
called foliation. Examples are gneiss, phyllite, schist, and slate.
Nonfoliated metamorphic rocks. It has no foliation or bands. Examples of this type are hornfels,
marble, quartzite, and novaculite.
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 What’s More

Direction: Complete the table below.

Classification
Rock Sample (Igneous, Sedimentary, Subclassification
Metamorphic)
1. Quartzite

2. Chemical
3. Intrusive
4.Gneis

5. Clastic

What have I Learned

Direction: Read and complete the following statements by filling in the blanks.

1. _______________ is a naturally occurring solid aggregate of minerals and sometime with non-mineral
solid particles.
2. Rocks can be classified based on _______________.
3. _______________are formed through solidification or crystallization of molten materials such as
magma and lava.
4. _______________ are formed through compaction and cementation of sediments and other materials
usually under the ocean or other bodies of water.
5. _______________ are formed either by heat such those near a magma chamber or by pressure such
those in the area with compression of rock layers.
6. Granite is an example of _______________ with visible large crystals because it solidified underneath
the Earth surface.
7. Sandstone is an example of _______________ rock from compaction and cementation of sand under
the ocean.
8. Marble is an example of _______________that has been formed due to heat and appears physically
different from its parent-rock called _______________.
9. Igneous rock can be classified into ______________ and ____________________.
10.__________________ metamorphic rock contains bands and ________________ metamorphic
rocks do not have bands.
11.Sedimentary rocks can be grouped according to _______________, ___________________ and
____________________.
12.___________________ formed from the mechanical weathering debris of rocks.
13. Chemical sedimentary rocks are formed when ______________________________.
14. ___________________ are formed from the debris of plants and animals.
15. ____________________ are metamorphic rocks that has no foliation.

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 What I can Do

Directions: Answer the question below.

While mountain trekking, Mayumi found several rocks that contained remains of aquatic plants
and animals.
1. What kind of rock did she find?
2. What can you infer on the formation of the rock?

Assessment

Directions: Choose the letter of the best answer. Write the letter on the answer sheet.

1. Ava collected samples of sedimentary rocks from the riverbank of Baclayon. She grouped the rocks
according to their characteristics. On the first group, she observed attached shells on the samples. While
on the second group, she observed pebbles attached on it. What type of sedimentary rocks did Ava
collect from the riverbank?
a. The first group is clastic sedimentary rocks while the second is chemical sedimentary rock.
b. The first group is clastic sedimentary rocks while the second is organic sedimentary rock.
c. The first group is chemical sedimentary rocks while the second is clastic sedimentary rock.
d. The first group is organic sedimentary rocks while the second is clastic sedimentary rock.
2. Which of the following describes a rock?
1. Solid 2. Heavy 3. Naturally occurring 4. Aggregate of minerals
a. 1, 2 and 3 c. 1, 2 and 4
b. 1, 3, and 4 d. 2, 3 and 4
3. Which of the following is a classification of sedimentary rock?
a. intrusive rock c. chemical rock
b. foliated rock d. non foliated rock
4. A rock sample was recovered from Taal Volcano Island by a local. The resident volcanologist was on
site and identified the rock was formed from the material ejected by the volcano during its eruption. He
further observed that the rock sample had glassy appearance. What type of rock did the local recover?
a. Extrusive rock c. Metamorphic rock
b. Intrusive rock d. Sedimentary rock
5. Which of the following statement is not true about metamorphic rocks?
a. It is formed from plant and animal debris.
b. It is formed when subjected to high heat and pressure.
c. Schist, phyllite and gneiss are examples of sedimentary rocks.
d. Foliated and non-foliated are classification of sedimentary rocks.
6. While walking at the beach, Angela found a rock sample with a crystal white appearance which
according to her friend was halite – a rock salt. What type of rock did she find?
a. Clastic rock c. Metamorphic rock
b. Chemical rock d. Organic rock
7. When magma solidifies on the surface of Earth, what possible igneous rock may be formed?
a. gabbro b. granite c. peridotite d. scoria
8. Obsidian is rock formed through fast solidification on air when a volcano erupts. What type of rock is
obsidian?
a. Extrusive igneous rock c. Intrusive igneous rock
b. Extensive igneous rock d. Intensive igneous rock

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9. Rinzen found an igneous rock from the school ground. Out of curiosity, she strongly hit the rock
sample by a hammer and found out that it had a glassy appearance. What is the correct inference on
the formation of the rock sample?
a. It formed overtime through slow process of crystallization beneath the surface of the Earth.
b. It formed overtime through fast process of crystallization beneath the surface of the Earth.
c. It formed overtime through slow process of crystallization at the surface of the Earth.
d. It formed overtime through fast process of crystallization at the surface of the Earth.
10.Which type of rock contains plants and animals remains?
a. Chemical rock c. Foliated rock
b. Clastic rock d. Organic rock
11.Which of the following statements is not true about igneous rocks?
a. It formed crystals. c. It can become glassy in appearance.
b. It is formed from magma. d. It can be formed from an existing rock.
12.Which of the following is excluded from the group?
a. gabbro b. granite c. pegmatite d. Shale
13.In spite of intense heat and pressure, nonfoliated rocks did not formed bands. Which of the following
rocks are nonfoliate?
a. Gneiss b. marble c. phyllite d. slate
14. Which of the following rock contains less crystals?
a. diorite b. granite c. pegmatite d. rhyolite
15. Which group of rocks formed from precipitate of dissolved materials?
a. Clastic rock c. Foliated rock
b. Chemical rock d. Organic rock

Additional Activities

There are more examples of rocks other than what you recognized in this lesson. This time,
widen your knowledge about rocks by identifying more examples of igneous, sedimentary and
metamorphic rocks in your area. Make a log and collect pictures of your samples and form a gallery.
You may search in the internet or ask an expert to assist you in identifying the samples you have
collected.

What I Need to Know

This module was designed and written to help you master the concept on the important minerals
to society.

After going through this module, you are expected to:

1. identify the minerals important to society; (S11ES-Ic-7)

2. explain the uses of the minerals that are important to society.

Earth Science Minerals Important to Society

Lesson 2
This lesson contains significant activities in which you will be able to identify the different minerals
important to society. At the end of this lesson, you can identify these common minerals and their uses.

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 What’s In

In your previous lesson, you learned the different types of rocks such as igneous rock,
sedimentary rock and metamorphic rock. Found within the rocks, deep under the Earth, are minerals
that people extract for everyday use. These minerals are very vital for our everyday living and for our
nation building. In this lesson, you will recognize some common minerals that are vital to society.

What’s New

Directions: Can you identify the minerals present in your kitchen? List down at least 5 objects as you
can.

Kitchen Object Mineral/s Present

1.
2.
3.
4.
5.

Guide Questions:

1. What minerals do you think are common in the kitchen?

2. Can you possibly think of alternative materials other than minerals to make up all the equipment and
wares in the kitchen?
3. Do you think minerals are really important to society? Why?

What is It

Minerals are important to society. In small scale, let us think of some ways that will help you to
realize that you are actually using them every day.
In households, we use toothpaste that contains fluoride from fluorite mineral. Face powder
contains talc – the softest mineral. In the kitchen, salts are commonly used to enhance the flavor of our
food. Kitchen utensils like casserole are made of aluminum – a light and durable metal, and stainless
wares that contains mostly of iron, chromium and carbon. Moreover, minerals such as silicon, silver
and gold are used as components of gadgets like cellphones and computers. Copper is the mostly
used electrical wiring because it is less expensive.
In construction, skyscrapers that tower up to 50 stories high, use durable minerals like iron steel
– a combination of iron and carbon and concrete that contains limestone, lime and chalk that make
them strong and stand still against strong wind and earthquake. They also use glass made mainly of
quartz and silica. Floors are made up of granite and marbles. Aluminum are used in window and
door panels.
In taking care of our dental health, Dentists use many tools appropriate for a purpose. Titanium
is a strong but very light metal that is used for teeth transplant. There are also lots of other minerals that
they use for cleaning and surgery. Examples are gypsum in plaster cast, and alloys like stainless steel
that primarily composed of iron, chromium and carbon in their tools.

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 Power plants use minerals to provide us electricity and energy. In nuclear power plant,
radioactive minerals like Uranium is used as source of heat energy to run a nuclear reactor. Likewise,
coal power plants also use mineral coal to generate electricity. On the hand batteries for electric cars
need minerals like nickel, copper, and lithium.
In agriculture, NPK Fertilizers contain vital minerals for the plant to grow healthy. These minerals
include Nitrogen, phosphorous and potassium. Moreover, minerals like lime are also used to lower
the acidity of the soil.
For our health, the pharmaceutical industry manufactures supplements that contain many
essential minerals that keep us strong and healthy like Calcium, Magnesium and Zinc.
On the other hand, minerals can also cause harm among humans. Talc might contain asbestos
that can cause certain cancer which is why some cosmetic companies discontinue using it. Nuclear
power plant that uses radioactive minerals produces radioactive waste. Burning of coals releases high
amount of carbon dioxide and other gases that contributes to the global warming. Over using of synthetic
fertilizer causes eutrophication of bodies of water.

What’s More

Directions: Find 10 minerals hidden in the puzzle that are used in making Jewelry. Write your answer
on your answer sheet.

X K O Z Z Q M K L R S L C T T
I L C D H O D Y E G E H R Y G
D N O M A I D P S G R P J W O
L L I U I H P L S O P W G P D
R C A M B O W U M R E G A W O
U N P R C V F I L E N L O M D
B I C P E S U C Q V T W V L K
Y U D U G M H V R L I E B F D
M Z G A R N E T E I N Q L X O
K M R K J I H N K S E G N A L

What have I Learned

Direction: Supply the minerals used in the different sectors.

Mineral Sector
1.
Mineral used in Energy
2.
Mineral used in Medicine 1.
2.
1.
Mineral used in Agriculture 2.
3.
Mineral used in Construction 1.
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 2.
3.
1.
2.
Mineral used in Household 3.
4.
5.

What I can Do
Direction: Give the uses of the following minerals in the society.

Mineral Uses/Importance
Halite (salt)
Granite
Quartz
Gold
Aluminum

Assessment
Multiple Choice: Choose the letter of the best answer. Write the letter on a separate sheet of paper.

1. Nutrients are essential substances needed by plants to grow. However, due to improper farming,
essential nutrient are depleted in soil. That is why, farmers use fertilizer to supplement the minerals lost.
What are the components of fertilizers?
a. aluminum, iron and copper c. calcium, magnesium and potassium
b. potassium, nitrogen, and carbon d. potassium, phosphorus, and nitrogen
2. Which of the following minerals is used as additive for different cosmetic materials like face powder?
a. Charcoal b. Coal c. Rock Salt d. Talc
3. Titanium is a light, durable and non-allergenic metal. In which industry is it not suitable for use? 1.
Agriculture 2. Energy production 3. Medical industry 4. Plastic making industry
a. 1, 2 and 3 b. 1, 2 and 4 c. 1, 3 and 4 d. 2, 3 and 4
4. In the era of climate change awareness due to air pollution caused by fossil fuel operated vehicles,
inventors developed electric powered car. This car uses batteries as energy storage. What are the
mineral components of these batteries?
a. Nickel, copper and lithium c. Nickel, lithium and zinc
b. Nickel, copper and zinc d. Nickel, silver and zinc
5. Which of the following minerals is usually used in households to enhance food taste?
a. Charcoal b. Coal c. Rock d. Salt Talc
6. Iron is a corrosive metal and forms rust once exposed to air. Manufacturers use stainless steel in
making safe kitchen wares. Which primary mineral is combined with iron and carbon to form stainless
steel?
a. Chromium b. Nickel c. Silicon d. Titanium
7. Which of the following semi metallic minerals is mostly used as electrical components for gadgets
and computers?

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 a. antimony b. boron c. germanium d. silicon

8. Nuclear energy is one of the cleanest and efficient energy sources. Which of the following minerals
is used as a source of this type of energy?
a. Calcium b. Chromium c. Titanium d. Uranium
9. Which of the following metals are mainly used as aircraft components because of their lightness and
durability?
a. Aluminum b. Chromium c. Titanium d. Uranium
10. Tooth extraction leaves an empty gum that affects an individual’s speaking and eating ability. To
address this problem, dentists use light metallic mineral to implant tooth on the affected gum. What
metallic mineral is used by the dentists?
a. Aluminum b. Calcium c. Titanium d. Uranium
11.What mineral is important in making toothpaste to fight tooth decay?
a. Calcium b. Chlorite c. Fluorite d. Fluoride
12.What are the minerals that composed glasses which are also used to produce kitchen wares?
a. Quartz and nickel c. Silica and chromium
b. Quartz and silica d. Silica and nickel
13.What organic mineral are used as a source of energy by some power plants in the Philippines?
a. charcoal b. chromium c. coal d. uranium
14.Silver is more conductive than copper. In spite of this, why do you think silver is not commonly used
in electrical wiring?
a. Silver is harder than copper. c. Silver is more abundant than copper
b. Silver is more malleable than copper. d. Silver is more expensive than copper.
15. Which of the following mineral can reduce soil’s acidity?
a. Coal b. Gypsum c. Lime d. Quartz

Additional Activities
‘

Directions: Do the following.

Have a research on the different minerals mined in the Philippines. Locate the areas where the
minerals are mined and identify their uses.

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References
Commission on Higher Education. Teaching guide for Senior High School: Earth Science Core
Subject. Quezon City: CHED, 2016.

“Construction minerals.” Minerals UK: Center for Sustainable Mineral development. British Geological
Survey. Accessed May 21, 2020. https://www.bgs.ac.uk/mineralsUK/planning/construction.html

“Fertilizer 101: The Big 3 - Nitrogen, Phosphorus and Potassium.” The Fertilizer Institute. Accessed
May 21, 2020. https://www.tfi.org/the-feed/fertilizer101-big-3-nitrogen-phosphorus-and-potassium

Tarbuck, Edward J., Lutgens, Frederick, K. Earth Science 10th Edition. Pearson Education, Inc. Upper
Saddle River, New Jersey. 2003

For inquiries and feedback, please write or call:

Department of Education – Division of Bohol

Office Address: 0050 Lino Chatto Drive, Brgy. Cogon, Tagbilaran City, Bohol
Telephone Nos.: (038) 412-4938; (038) 411-2544; (038) 501-7550
Telefax: (038) 501-7550
E-mail Address: deped.bohol@deped.gov.ph

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