EARTH AND LIFE SCIENCE |MODULE 1

Unlocking Difficulties:
LESSON 1: UNIVERSE AND THE SOLAR SYSTEM
Earth is characterized by its blue waters,
Most Essential Learning Competency: rocky brown and green land masses with
● Recognize the uniqueness of Earth, being white clouds set against a black background.
the only planet in the solar system with It is the third planet from the Sun and a few
properties necessary to support life. hundred kilometres larger than planet Venus
in terms of diameter. Also, it is the fifth largest
(S11/12ES-Ia-e- 3)
planet in the solar system. It is the only known
Objectives:
planet that can support life. Our home planet
At the end of the lesson, students are expected to: is special because 70% of its surface is
● Define the concept of a system; covered by water.
● Recognize the Earth as a system composed of
subsystems; and Earth is made up of erratic, complex and
● Discuss the historical development of the concept interactive systems that make it a constantly
of the Earth System. changing planet. Earth Science (also known
as geosciences), is a comprehensive term
Pretest: used for all sciences related to earth geology,
meteorology, oceanography etc.
Directions: Write the letter of the correct answer that
best completes the sentence or answers the question. Air, water, land and life are the four major
systems of Earth. Each helps shape the
1. Which statement describes the atmosphere of the structure of the planet. A system is defined as
planet correctly? a group of independent parts that work
together as a whole.
A. Venus is mostly carbon dioxide.
B. Earth is mostly oxygen. Exercises:
C. Mercury is mostly nitrogen.
D. Saturn is mostly helium. Activity #1:Compare and Contrast. What are the
similarities and differences among these three
2. To weigh roughly two-thirds less than what you do terrestrial planets?
on Earth, which planet would you be on?
Objective: Recognize the difference in the physical
A. Uranus B. Mars and chemical properties between the Earth and its
C. Venus D. Jupiter neighboring planets.

3. How long does it take for light from the Sun to reach
Earth?

A. 1 minute B. 8 minutes
C. Instantaneous D. 24 hours

4. The habitable zone is also referred to as the:

Figure 1. Venus, Earth, and Mars. Images from NASA

A. Gaeia B. Theia
C. Solar nebula D. Goldilocks
condition
Procedure:
1. Look for a photograph (internet/books/posters) of
5. Of the nine known planets, what planet have one or terrestrial planets Venus, Earth, and Mars. If possible,
more natural satellites place photographs side by side.

A. Venus & Mercury B. Earth & Venus 2. Write down on a piece of paper similarities and
C. Jupiter & Mars D. Earth & Mercury differences among the planets. Use Table 1 for your
reference.

Recall: 3. Provide possible explanations for your observations

using the information in Table 1, together with
previous knowledge about the planets.
TERRESTRIAL or GAS Planet
Directions: Identify the planet whether a
TERRESTRIAL or GAS planet.

1.Venus- ________________________
2.Saturn- ________________________
3.Earth- _________________________
4.Mars-__________________________
5.Uranus- ________________________

1
EARTH AND LIFE SCIENCE |MODULE 1
References:
Activity #2: Interstellar Crash Landing

Exploring Life through Science: Earth and Life

Science by Jose Tolentino Olivar II and Anna Cherylle
Morales- Ramos Phoenix Publishing House, 2016

Earth and Life Science: Teaching Guide for Senior

High School; Philippine Normal University, published
by Commission on Higher Education

Retrieved from:

https://www.nap.edu/resource/12161/origin_and_evol
ution_of_earth_final.pdf
Objective: Identify the factors that allow a planet to https://www.lpi.usra.edu/education/explore/our_place
support life. /hab_ref_table.pdf
Procedure:
1. On a piece of paper, create a list of items that you
would need to bring with you to survive an extended
trip on a spaceship into space (the supplies that are
necessary for life as we know it). You should think
beyond what humans would need, and to consider the
needs of other forms of life that humans might bring
along (for example: plants for food/medicine, animals
for food/companionship).

2. Once you have developed lists of what you would

need, imagine that something has gone terribly wrong
on your well-packed spaceship and that you need to
crash land in the nearest planetary system.
Fortunately, you are passing through the Yanib
System, which is composed of a sun-like star
surrounded by seven planets, some of which have
moons. The profiles of planets and moons of the Yanib
System are listed on Table 3.

3. Write down on a piece of paper your choice of

planet or moon. Reasons for your choice should also
be written down as well as the reasons why you did
not choose the other planets.

Posttest: On a separate sheet of paper, answer each

item correctly.

Terraforming Mars: Have the learners write

a 200 word report/essay on the following
topic: ‘Can man alter Mars environment to
make it more suitable for human habitation?
How?’

2
EARTH AND LIFE SCIENCE |MODULE 1
LESSON 2: EARTH SUBSYSTEMS

Most Essential Learning Competency:

● Explain that the Earth consists of four
subsystems, across whose boundaries
matter and energy flow.
(S11/12ES-Ia-e- 4)

Objectives:
At the end of the lesson, students are expected to:
● Define the concept of a system;
● Recognize the Earth as a system composed of
subsystems; and
● Discuss the historical development of the concept
of Earth System.
Source:http://3.bp.blogspot.com/_YTb6ZblJu0o/TPMzp32R5aI/AAAAAAAAALg/vnul9Zg
Wt0M/s1600/WaterCycleArt.jpg
Pretest:
Unlocking Difficulties:
Directions: Write the letter of the correct answer that
● The lithosphere contains all of the cold, hard
best completes the sentence or answers the question.
solid land of the planet's crust (surface), the semi-
solid land underneath the crust, and the liquid
1. Choose the most appropriate description of the
land near the center of the planet.
hydrosphere.
● The hydrosphere contains all the solid, liquid, and
A. The mixture of gases that surrounds the earth.
gaseous water of the planet.
B. The waters on earth including subsurface.
● The biosphere contains all the planet's living
C. Only surface water on earth.
things. This sphere includes all of the
D. Only atmospheric water.
microorganisms, plants, and animals of Earth.
● The atmosphere contains all the air in Earth's
2. All living organisms of the earth, including those on
system. It extends from less than 1 m below the
the land, water, and air, are considered part of
planet's surface to more than 10,000 km above
which subsystem?
the planet's surface.
A. biosphere B. atmosphere
C. hydrosphere D. geosphere
Discussion:
3. Which of the following is NOT one of the four Our diverse planet Earth has many different features
major geological subsystems of the earth? that can be studied from space. One way of studying
A. biosphere B. watersphere Earth is by taking an Earth Systems Science
C. atmosphere D. geosphere approach.

4. The crust of the earth consists mostly of: Earth Systems Science involves looking at Earth as
A. oxygen & silicon B. iron & silicon a set of systems. These systems are all connected
C. iron & nickel D. copper & nickel and influence one another, as well as, the Earth as a
whole. Each individual system consists of features,
that together, play a role in keeping our Earth in
5. The layer that makes up most of the earth’s mass
balance. A change within one system will cause a
and volume is the:
change in another. The past, present, and future of our
A. mantle B. magma planet is based on the constant interaction among
C. crust D. core these systems.

Recall: The biosphere is associated with living systems such

Label the different processes of water involved in the as biomes and ecosystems. This includes organisms
water cycle. on land, in various bodies of water, and even life we
cannot see with the naked eye. The atmosphere
a. Condensation d. Transpiration relates to meteorological features and phenomena
b. Precipitation e. Infiltration such as weather, clouds, or aerosols (particles in the
c. Evaporation f. Surface run-off air). It includes an ever‐changing mixture of gas and
small particles located surrounding and above the
Earth’s surface.

The hydrosphere is associated with water in solid

(ice) and liquid states. Water in a gas state (water
vapor) can be also considered as a feature of the
atmosphere. Water vapor is invisible, but we can track
the movement of water by its interactions. The term
cryosphere specifically refers to water in the form of
ice on Earth.

3
EARTH AND LIFE SCIENCE |MODULE 1
The geosphere is associated with solid portions of the 3. Core- At the planet’s center lies a dense metallic
Earth. It includes rocks, sediments and soils, surface core. Scientists know that the core is metal for a few
landforms and the processes that shape the Earth’s reasons. The density of Earth’s surface layers is much
surface. Features associated with this sphere can be less than the overall density of the planet, as
broken down into a variety of different processes and calculated from the planet’s rotation. If the surface
related surface landforms. Some examples include: layers are less dense than average, then the interior
erosion, volcanism, and plate tectonic movement. must be denser than average. Calculations indicate
Alternate terms that also refer to these terrestrial that the core is about 85 percent iron metal with nickel
features are lithosphere or crust. metal making up much of the remaining 15 percent.
Also, metallic meteorites are thought to be
Layers of the Earth representative of the core.If Earth’s core were not
1. Crust- Earth’s outer surface is its crust; a cold, thin, metal, the planet would not have a magnetic field.
brittle outer shell made of rock. The crust is very thin, Metals such as iron are magnetic, but rock, which
relative to the radius of the planet. There are two very makes up the mantle and crust, is not. Scientists know
different types of crust, each with its own distinctive that the outer core is liquid and the inner core is solid
physical and chemical properties. Oceanic crust is because S-waves stop at the inner core. The strong
composed of magma that erupts on the seafloor to magnetic field is caused by convection in the liquid
create basalt lava flows or cools deeper down to outer core. Convection currents in the outer core are
create the intrusive igneous rock gabbro. Sediments, due to heat from the even hotter inner core. The heat
primarily muds and the shells of tiny sea creatures, that keeps the outer core from solidifying is produced
coat the seafloor. Sediment is thickest near the shore by the breakdown of radioactive elements in the inner
where it comes off the continents in rivers and on wind core.
currents. Continental crustis made up of many
different types of igneous, metamorphic, and
sedimentary rocks. The average composition is
granite, which is much less dense than the mafic
igneous rocks of the oceanic crust. Because it is thick
and has relatively low density, continental crust rises
higher on the mantle than oceanic crust, which sinks
into the mantle to form basins. When filled with water,
these basins form the planet’s oceans. The
lithosphere is the outermost mechanical layer, which
behaves as a brittle, rigid solid. The lithosphere is
about 100 kilometers thick. The definition of the
lithosphere is based on how earth materials behave,
so it includes the crust and the uppermost mantle,
which are both brittle. Since it is rigid and brittle, when INTERACTIONS BETWEEN 4 SPHERES
stresses act on the lithosphere, it breaks. This is what Although the four systems have their individual
we experience as an earthquake. identities, there is important interaction between them.
Environmental scientists study the effects of events in
2. Mantle- The two most important things about the one sphere on the other spheres. There are ten
mantle are: (1) it is made of solid rock, and (2) it is hot. possible types of interactions that could occur within
Scientists know that the mantle is made of rock based the earth system. Four of these interactions are
on evidence from seismic waves, heat flow, and between the event and each of the earth's spheres.
meteorites. The properties fit the ultramafic rock The double-headed arrows indicate that the cause
peridotite, which is made of the iron- and magnesium- and effect relationships
rich silicate minerals. Heat flows in two different ways of these interactions go
within the Earth: conduction and convection. in both directions.
Conduction is defined as the heat transfer that occurs These four types of
through rapid collisions of atoms, which can only interactions can be
happen if the material is solid. Heat flows from warmer illustrated in Figure #1.
to cooler places until all are the same temperature. The "event <>
The mantle is hot mostly because of heat conducted hydrosphere" refers to
from the core. Convection is the process of a material the effects of the event
that can move and flow may develop convection on the hydrosphere, as
currents. Convection in the mantle is the same as well as the effects of the
convection in a pot of water on a stove. Convection hydrosphere on the
currents within Earth’s mantle form as material event. For example, a volcanic eruption in the
near the core heats up. As the core heats the geosphere may cause profound direct and indirect
bottom layer of mantle material, particles move effects on the hydrosphere, atmosphere and
more rapidly, decreasing its density and causing biosphere as follows.
it to rise. The rising material begins the convection
current. When the warm material reaches the surface, Volcano >> lithosphere >> atmosphere >>
it spreads horizontally. The material cools because it hydrosphere >> biosphere
is no longer near the core. It eventually becomes cool
and dense enough to sink back down into the mantle. Volcanoes (an event in the lithosphere) release a
At the bottom of the mantle, the material travels large amount of particulate matter into the
horizontally and is heated by the core. It reaches the atmosphere. These particles serve as nuclei for the
location where warm mantle material rises, and the formation of water droplets (hydrosphere). Rainfall
mantle convection cell is complete. (hydrosphere) often increases following an eruption,

4
EARTH AND LIFE SCIENCE |MODULE 1
stimulating plant growth (biosphere). Particulate B. AQUARIUM SYSTEM VS EARTH SYSTEM
matter in the air (atmosphere) falls out, initially
smothering plants (biosphere), but ultimately With the use of the aquarium again, try to identify
enriching the soil (lithosphere) and 4 thereby which parts of it could represent the different spheres
stimulating plant growth (biosphere). of the Earth.

a. Hydrosphere = ___________________

b. Atmosphere = ___________________

c. Biosphere = ___________________

d. Geosphere = ___________________

Generalization:
1. James Lovelock used the "Daisy World Model" to
illustrate how the biosphere is capable of regulating
its environment.

2. Try to research and write a two page report (50 to

100 words, with illustrations) on the "Daisy World
Model" of James Lovelock.

Posttest:On a separate sheet of paper, answer each

items correctly.
Exercises:
1. Where is the mantle found?
A. between the crust and the core
A. AQUARIUM SYSTEM
B. the innermost part of the Earth
1. Observe an aquarium (real, video, picture) and C. the outermost part of the Earth
reflect on the following questions: D. beneath the tectonic plates

a. What are the different parts found in our 2. Which is the hottest part of the Earth?
aquarium? A. the mantle C. the crust
____________________________________ B. the inner core D. the outer core

b. How are these parts alike? What do they 3. Which among the layers of the Earth internal
have in common? structure is the densest layer?
A. crust C. core
____________________________________ B. mantle D. inner mantle
c. How are they different?
4. Earth outermost layer is __________.
____________________________________ A. inner core C. outer core
B. mantle D. crust
d. How do they work together in the aquarium
system? 5. The Earth’s core is made up of?
A. rock and salt C. metal and gold
____________________________________
B. rock and metal D. gold and salt
e. What interactions do they have together?
References:
____________________________________

f. How do these interactions change the Exploring Life through Science: Earth and Life
aquarium system? Do they help the system? Science by Jose Tolentino Olivar II and Anna Cherylle
Morales- Ramos Phoenix Publishing House, 2016
____________________________________
Earth and Life Science: Teaching Guide for Senior
g. What could change the aquarium system?
High School; Philippine Normal University, published
____________________________________ by Commission on Higher Education

2. Try to discuss with your partner how these parts are Retrieved from:
connected in their aquarium and investigate how they http://resources.bishopmuseumeducation.org/resourc
represent similar connections found on Earth. e_type/lesson/3.1.2_NASA_Celestial_Islands_Lesso
n.pdf

https://www.esrl.noaa.gov/gmd/education/info_activiti
es/pdfs/TBI_earth_spheres.pdf

5
EARTH AND LIFE SCIENCE |MODULE 1
LESSON 3: MINERALS AND ROCKS Recall:
Answer the following questions:
Most Essential Learning Competency:
● Identify common rock-forming minerals using 1. Do you consider water a mineral?
their physical and chemical properties.
(S11/12ES-Ia-9)
Objectives:
At the end of the lesson, students are expected to:
● Demonstrate understanding about physical and
chemical properties of minerals;
● Identify some common rock-forming minerals; and
● Classify minerals based on chemical affinity.

Pretest: 2. Do you consider tube ice a mineral?

Directions: Write the letter of the correct answer that

best completes the sentence or answers the question.

1. What is an example of a defining attribute of a

mineral?
A. Definite chemical composition
B. Naturally occurring
C. Liquid or Gas
D. Man Made

2. How do you test the hardness of a mineral?

A. Throw it against a wall
B. Step on it 3. Do you consider snowflake a mineral?
C. Scratch Test
D. Kick it until it breaks

3. What scale is used to test the hardness of a

mineral?
A. Mineral Hardness Scale
B. Moh’s Hardness Scale
C. Hom’s Hardness Scale
D. Shom’s Hardness Scale

4. How effective is the physical property of color in

identifying a mineral?
A. very effective. You can immediately identify it *Answer: Tube ice is not a mineral, because it is not
based only on the color. naturally occurring. But a snowflake possesses all the
B. It doesn't make a difference. Every mineral properties under the definition of a mineral.
can be any color.
C. It is one property and may not be used alone to Unlocking Difficulties:
identify a mineral. ● Luster – it is the quality and intensity of reflected
D. Color isn't a physical property. light exhibited by the mineral.
5. How do you test the streak of a mineral? ● Hardness – it is a measure of the resistance of a
A. By scraping some of the mineral onto a streak mineral (not specifically surface) to abrasion.
plate. ● The external shape of a crystal or groups of
B. Look for streaks on the mineral. crystalsis displayed / observed as these crystals
C. Google it. grow in open spaces. The form reflects the
D. You don’t. supposedly internal structure (of atoms and ions)
of the crystal (mineral). It is the natural shape of
the mineral before the development of any
cleavage or fracture.
● A mineral’s color is caused by the absorption,
or lack thereof, of visible light by their crystalline
structure.

Discussion:

As this class deals with earth materials and

processes, it is important that we gain knowledge of
the materials that make up the Earth’s crust. The rocks

6
EARTH AND LIFE SCIENCE |MODULE 1
that make up the Earth and the minerals that compose 1. Luster
them have significant effects on our lives. Luster describes the appearance of a mineral when
light is reflected from its surface. Is it shiny or dull:
The minerals that we will study here represent the does it look like a metal or like glass? Generally the
most common rock-forming minerals plus the most first thing you notice when identifying an unknown
important economic minerals. These are of interest to sample is the mineral’s luster. Important examples of
us because a good understanding of the physical and mineral luster are shown in Figure 1 below.
chemical oceanographic processes we will be
learning about in this class requires a good
understanding of the solid materials that are at the
core of these processes.

To understand the relationship between minerals and

rocks, imagine a Snickers candy bar. It is made up of
several different materials: chocolate, nuts, caramel,
and nougat (whatever the heck that is). A rock is, like
that candy bar, an aggregate of distinctive 2. Color
components; the components are, like minerals, Color is one of the most obvious properties of a
homogeneous substances with properties that mineral but it is often of limited diagnostic value,
distinguish them from each other. especially in minerals that are not opaque. While
many metallic and earthy minerals have distinctive
Minerals differ from each other in chemical colors, transucent or transparent minerals can vary
composition and architecture, and these factors widely in color. Quartz, for example, can vary from
produce distinctive physical properties that enable colorless to white to yellow to gray to pink to purple to
minerals to be identified. The most useful physical black (Figure 2). On the other hand the colors of some
properties for identifying minerals are examined here. minerals, such as biotite (black) and olivine (olive
green) can be distinctive. Never use color as a final
What Is A Mineral? diagnostic property -- check other properties before
A mineral satisfies all four of the following criteria: making an identification.
● It is a naturally occurring substance.
● It is an inorganic substance.
● It has an orderly internal structure, and;
● It has a fixed, (or uniformly variable) chemical
composition.

That they are naturally occurring and inorganic

separates minerals from most manufactured
substances as well as materials formed only in
biological processes. Their internal structure and
chemical composition gives minerals characteristic
physical and chemical properties that provide clues to
the identity of the minerals.
3. Streak
Most minerals form by inorganic processes but some, Streak refers to the color of the mineral in its powdered
identical in all respects to inorganically formed form, which may or may not be the same color as the
minerals, are produced by organic processes (for mineral. Streak is helpful for identifying minerals with
example, the ncalcium carbonate in the shells of metallic or earthy luster, because (with a few
clams or snails). A few naturally occurring substances exceptions) minerals with nonmetallic luster generally
called mineraloids have characteristic chemical have a colorless or white streak that is not diagnostic,
compositions but are amorphous. Opal is an example. Streak is obtained by scratching the mineral on an
unpolished piece of white porcelain called a streak
The precise chemical composition and internal atomic plate (Figure 3). Because the streak plate is harder
structure that defines each mineral also directly than most minerals, rubbing the mineral across the
determines its outward appearance and physical plate produces a powder of that mineral. When the
properties. excess powder is blown away, what remains is the
Thus, in most cases, general appearance and a few color of the streak. Because the streak of a mineral is
easily determined physical properties are sufficient to usually the same, no matter what the color of the
identify the mineral. mineral, streak is commonly more reliable than color
for identification.

A. Physical Properties
Color, luster, streak, hardness, cleavage, fracture,
and crystal form are the most useful physical
properties for identifying most minerals. Other
properties-such as reaction with acid, magnetism,
specific gravity, tenacity, taste, odor, feel, and
presence of striations-are helpful in identifying certain
minerals.

7
EARTH AND LIFE SCIENCE |MODULE 1
4. Hardness without atoms. When halite breaks, it breaks parallel
Hardness is the resistance of a mineral to scratching to the planes with atoms but along the planes without
or abrasion by other materials. Hardness is atoms. Because there are three directions in which
determined by scratching the surface of the sample atom density is equal, halite has three directions of
with another mineral or material of known hardness. cleavage, each at 90° to each other. The number of
The standard hardness scale, called Mohs Hardness cleavage directions and the angles between them are
Scale (Table 1), consists of ten minerals ranked in important in mineral identification because they reflect
ascending order of hardness with diamond, the the underlying atomic architecture that defines each
hardest known substance, assigned the number 10. mineral.
The hardness kits we use in class contain only
minerals 2-7, as these are the most useful for testing
most of the minerals we will encounter in this class.
Since most of us don’t wander the outdoors with a
pocketful of standard minerals table one also lists the
relative hardness of other common items.

To determine hardness, run a sharp edge or a point of

a mineral with known hardness across a smooth face
of the mineral to be tested (Figure 4). Do not scratch
back and forth like an eraser, but press hard and
slowly scratch a line, like you are trying to etch a
groove in glass. Sometimes powder of the softer
Cleavage planes, as flat surfaces, are easily spotted
mineral is left on the harder mineral and gives the
by turning a sample in your hand until you see a single
appearance of a scratch on the harder one. Brush the
flash of reflected light from across the mineral surface.
tested surface with your finger to see if a groove or
scratch remains.
Individual cleavage surfaces may extend across the
whole mineral specimen (Figure 7) or, more
commonly, they may be offset from each other by
small amounts, as illustrated in Figure 1.8. Even
though they are offset, they work as tiny mirrors that
create the single flash seen in Figure 1.9. Figures 1.10
and 1.11A also show offset cleavage surfaces.
Cleavage quality is described as perfect, good, and
poor. Minerals with a perfect or excellent cleavage
break easily along flat surfaces and are easy to spot.
Minerals with good cleavages do not have such well-
A piece of glass is provided in the hardness kits as a defined cleavage planes and reflect less light. Poor-
standard for determining hardness. There are several cleavages are the toughest to recognize, but can be
reasons for this: spotted by small flashes of light in certain positions. All
● it is easy to see a scratch on glass; cleavages illustrated here are perfect or good.
● the hardness of glass (5 to 5½) is midway on
the Mohs scale; and
● glass is inexpensive and easily replaced.

Minerals have characteristic numbers of cleavages

5. Cleavage and Fracture (Figure 8). This number is determined by counting the
The way in which a mineral breaks is determined by number of cleavage surfaces that are not parallel to
the arrangement of its atoms and the strength of the each other. For example, the mineral in Figure 9 has
chemical bonds holding them together. Because two planes of cleavage, one that is visible and one
these properties are unique to the mineral, careful lying on the table. However, each of these cleavage
observation of broken surfaces may aid in mineral surfaces is parallel to the other, so this mineral is said
identification. A mineral that exhibits cleavage to have only one cleavage direction. Minerals with one
consistently breaks, or cleaves, along parallel flat cleavage are often said to have a basal cleavage.
surfaces called cleavage planes. A mineral fractures if
it breaks along random, irregular surfaces. Some
minerals break only by fracturing, while others both
cleave and fracture.

The mineral halite (NaCl, or sodium chloride)

illustrates how atomic arrangement determines the
way a mineral breaks. Figure 6 shows the
arrangement of sodium and chlorine atoms in halite.
Notice that there are planes with atoms and planes

8
EARTH AND LIFE SCIENCE |MODULE 1
Two cleavage directions are present when planes When counting cleavage directions it is essential that
of breakage occur along two non-parallel planes you count surfaces on just one mineral crystal. The
(Figures 8, 10). These two planes can be photographs shown here used single large, broken
perpendicular (at 90°) to one another, in which case crystals to illustrate cleavage. In nature you often find
the mineral is said to have prismatic cleavage. In that a single hand-sized sample contains a large
some minerals the two planes of cleavage may not number of crystals grown together (see following
be perpendicular – this is known as non-prismatic discussion under "Crystal Form"). If you count
cleavage. When there are two cleavages, you should cleavage surfaces from more than one crystal, a
note the angle between them. Most commonly, wrong number is likely.
cleavage angles are close to 60°, 90°, or 120°.

Finally, fracture surfaces can cut a mineral grain in any

direction. Fractures are generally rough or irregular,
rather than flat, and thus appear duller than cleavage
surfaces. Some minerals fracture in a way that helps
to identify them. For example, quartz has no cleavage
but, like glass, it breaks along numerous small,
smooth, curved surfaces called conchoidal fractures
(Figure 13). Though other kinds of fracture exist in
Some minerals have three planes of cleavage: If the nature, such as fibrous, splintery, or irregular,
three cleavages intersect at 90° the mineral is said to conchoidal fracture is the only type we will concern
have cubic cleavage (Figures 8, 11A): If none of the ourselves with here.
cleavage planes intersect at right angles the shape is
a squashed cube known as a rhombohedron (called In the field you will often have to break samples into
rhombohedral cleavage -- Figures 8, 11B). A third pieces to observe cleavages and fractures on fresh
variant occurs when a mineral has two cleavage surfaces. While it is instructional (and fun!) to hammer
planes that are perpendicular, and a third that is not some mineral samples yourself, do not break the lab
perpendicular to the other two (Figure 11C). samples without your instructor's approval! Samples
cost money and in most cases have already been
broken to show characteristic features.

6. Crystal Form
A crystal is a solid, homogeneous, orderly array of
atoms and may be nearly any size (Figure 14). The
arrangement of atoms within a mineral determines the
external shape of its crystals. Some crystals have
smooth, planar faces and regular, geometric shapes;
these are what most people think of as crystals. These
crystals occur only rarely in nature however, because
in order to develop those beautifully-shaped faces the
mineral must have unlimited space in which to grow.
Minerals with four or six cleavage directions are not
common. Four cleavage planes can intersect to form
an eight sided figure known as an octahedron (Figure
12). Fluorite is the most common mineral with an
octahedral cleavage. Six cleavage directions intersect
to form a dodecahedron, a twelve-sided form with
diamond-shaped faces. A common mineral with
dodecahedal cleavage is sphalerite (Figure 13).

When a mineral begins to solidify, either due to the

cooling of molten material or due to precipitation from
a solution, microscopic crystals always form and grow.
These tiny crystals will continue to grow until they run
out of space. At this point their external shape will
simply reflect the shape of the void which they grew.
If the growing crystal runs out of material before it runs
out of space, you will be left with a nicely shaped
crystal within an otherwise empty void such as a
geode.

9
EARTH AND LIFE SCIENCE |MODULE 1
1. Magnetism
Some minerals are attracted to a hand magnet. To test
a mineral for magnetism, just put the magnet and
mineral together and see if they are attracted.
Magnetite is the only common mineral that is always
strongly magnetic.

2. Reaction with Acid

Some minerals, especially carbonate minerals, react
visibly with acid. (Usually, a dilute hydrochloric acid
[HCl] is used.) When a drop of dilute hydrochloric acid
is placed on calcite, it readily bubbles or effervesces,
releasing carbon dioxide (Figure 18). BE CAREFUL
when using the acid -- dilute acid can burn your skin
(especially if you have a cut) or stain or put a hole in
your clothing. Only a small drop of acid is needed to
see whether or not the mineral bubbles. When you
finish making the test, wipe the acid off the mineral
immediately. Should you get acid on yourself, wash it
off right away; if you get it on your clothing, rinse it out
immediately.
Some minerals commonly occur as well-developed
crystals, and their crystal forms are diagnostic. A
detailed nomenclature has evolved to describe crystal
forms, and some of the common names may be
familiar For example, quartz commonly occurs as
hexagonal (six-sided) prisms with pyramid-like shapes
at the top (Figure 15). Pyrite occurs as cubes or
pyritohedrons (forms with twelve pentagonal faces)
(Figure 16). Garnets occur as dodecahedrons, 12- 3. Striations
sided forms that have a roughly round shape (Figure Plagioclase feldspar can be positively identified and
17). distinguished from potassium feldspar by the
presence of very thin, parallel grooves called striations
(Figure 19). The grooves are present on only one of
the two sets of cleavages and are best seen with a
hand lens. They may not be visible on all parts of a
cleavage surface. Before you decide there are no
striations, look at all parts of all visible cleavage
surfaces, moving the sample around as you look so
that light is reflected from these surfaces at different
angles. Until you have seen striations for the first time,
you may confuse them with the small, somewhat
Cleavage surfaces may be confused with natural irregular, differently colored intergrowths or veinlets
crystal faces; in fact, cleavage planes are parallel to seen on cleavage faces of some specimens of
possible (but not always developed) crystal faces. potassium feldspar (Figure 19). However, these have
They can be distinguished as follows: variable widths, are not strictly parallel, and are not
1. Crystal faces are normally smooth, grooves, so they are easily distinguished from
whereas cleavage planes, though also striations.
smooth, commonly are broken in a step-like
fashion;
2. Some crystal faces have fine grooves or
ridges on their surfaces (Figures 15, 16)
whereas cleavage planes do not. Similar
looking, very thin, parallel grooves, or
striations, are seen on plagioclase cleavage
surfaces, but these features persist
throughout the mineral and are not surficial, 4. Specific Gravity
as described below; The specific gravity of a mineral is the weight of that
3. Finally, unless crystal faces happen to mineral divided by the weight of an equal volume of
coincide with cleavage planes, the mineral will water. The specific gravity of water equals 1.0, by
not break parallel to them. definition. Most silicate, or rock-forming, minerals
have specific gravities of 2.6 to 3.4; the ore minerals
B. Additional Properties are usually heavier, with specific gravities of 5 to 8. If
Special properties help identify some minerals. These you compare similarsized samples of two different
properties may not be distinctive enough in most minerals, the one with the higher specific gravity will
minerals to help with their identification or they may be feel the heaviest; it has a greater heft. For most
present only in certain minerals. minerals, specific gravity is not a particularly
noteworthy feature, but for some, high specific gravity
is distinctive (examples are barite and galena).

10
EARTH AND LIFE SCIENCE |MODULE 1
5. Taste, Odor, Feel What happened?
Some minerals have a distinctive taste (halite is salt,
and tastes like it). some a distinctive odor (the powder 1. After rubbing your fingers over the rocks, how did
of some sulfide minerals, such as sphalerite, a zinc the surface feel?
sulfide, smells like rotten eggs), and some a distinctive
feel (talc feels slippery). 2. When the rocks were exposed to bright light, did
you see colors? What are they?
Exercises:
3. Using the hand lens, did you see particles on the
rocks? Can you describe them?
A. IDENTIFYING UNKNOWN MINERAL
PART 2: What to do?
1. Use the information about color, hardness, and
luster given in the three tables below to provide the 1. Determine the mass of each rock sample using the
name of the unknown mineral in the table at the platform balance or any other tool for weighing.
bottom of the page.
2. Measure the volume by applying the water
displacement method.

3. Calculate for the density of each rock sample.

4. Write your data on the table below:

ROCK MASS VOLUME DENSITY

SAMPLE (g) (cm3) (g/cm3)
A
B
C
D
E

What happened?

1. Which rock is most dense? Why?

2. Which rock is the least dense? Why?

What Now?
B. ROCK BABY ROCK!
1. Do rocks differs from one another? How do they
What you need? differ?
5 different rock samples
hand lens 2. What geologic findings would account for the
water difference in densities of rocks?
platform balance
strip of colored paper (for labeling) Generalization:

1. List five minerals and their common uses. Identify

PART 1: What to do? thespecific property/properties that makes the mineral
1. Label your rock samples A, B, C, D, E. suitable for those uses. For example, graphite, having
2. Rub your hands over each rock. Feel the texture of a black streak and hardness of 1-2, is used in pencils
the surface of each rock. due to its ability to leave marks on paper and other
3. Hold the rocks in such a way that bright light its objects.
surface. Observe carefully the surface.
4. Using a hand lens, examine closely the physical Posttest: On a separate sheet of paper, answer
make-up of the rock’s surface. each items correctly.
5. Write your description in the table below:
1. Which is the hardest mineral?
COLOR SIZE OF A. Calcite
ROCK TEXTURE (light, PARTICLES B. Diamond
SAMPLE (fine or dark or FOUND C. Quartz
course) glassy) (large, small D. Talc
or none)
A 2. Minerals are identified on the basis of:
B A. chemical and physical properties
C B. size of their crystals
D C. type of rock in which they are found
E D. method by which they are formed
TABLE 1

11
EARTH AND LIFE SCIENCE |MODULE 1
3. Scratching a mineral against a glass plate is a
method used for determining the mineral's:
A. color C. cleavage
B. hardness D. luster

4. The relative hardness of a mineral can best be

tested by:
A. determining the density of the mineral
B. breaking the mineral with a hammer
C. squeezing the minerals with calibrated pliers
D. scratching the mineral across a glass plate

5. You encounter a clear mineral in a vein within a

rock, which your instructor tells you is either
quartz, calcite, or gypsum. You can scratch it with
your pocketknife, but not your fingernail. Which is
it?
A. gypsum C. quartz
B. calcite D. can’t tell from the
information given

References:

Exploring Life through Science: Earth and Life

Science by Jose Tolentino Olivar II and Anna Cherylle
Morales- Ramos Phoenix Publishing House, 2016

Earth and Life Science: Teaching Guide for Senior

High School; Philippine Normal University, published
by Commission on Higher Education

Retrieved from:

https://www.saddleback.edu/faculty/jrepka/notes/GE
OmineralLAB_1.pdf

https://www.higp.hawaii.edu/~scott/GG101L/Jones2_
minerals_chapters.pdf

12