Science Rocks

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Teacher Background

In grade 4, students are expected to understand that rocks are porous. A rock that is porous allows a liquid or air to flow
through small spaces or holes in the rock. A rock that has been shaped through weathering and erosion may allow soil to
collect in or on it, which can provide locations for plants to grow. In grade 5, students will discuss the formation of
sedimentary rock and fossil fuels within those holes.

In kindergarten, students were introduced to physical properties of rocks when they sorted rocks by shape, size, color, and
texture. This is their second exposure to physical properties of rocks. Resources such as metals, gems, and ground water
and energy resources such as petroleum, natural gas, and heated water (geothermal energy) can be contained within layers
of rock. These resources are mined or drilled (wells).

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Lesson Vocabulary

physical properties

rock

size

color

hardness

texture

luster

Physical Property

A characteristic that
describes something

Rock

A hard, nonliving,
natural resource from
the Earth

Size

The total amount of
physical space that a
person or thing
occupies; how large or
small someone or
something is

Color

A characteristic such as
red, blue, green, yellow,
etc., that you see when
you look at something

Hardness

The quality of
something being hard.
The ability of a
substance to scratch
another substance or
be scratched

Streak

• A streak is a minerals powder that it leaves when rubbed on a porcelain plate.

• The minerals streak is not always the same as its outside color.

• The softer the mineral, the better streak it will leave. If the mineral is harder, you need to push down much more to see the streak.

Texture

How rough or smooth an
object feels

Luster

How the surface of
a mineral reflects
light.

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What do you notice or wonder?

How can you describe and sort these rocks?

Observe each rock. List the physical properties using the word

bank below.

Rock

Drawing

Size

Color

Hardness

Texture

Luster

small

medium

big

large

gray
white
clear
black

red

orange
yellow

soft

fragile
chalky
crumbly

firm

compact

tough
hard

bumpy

smooth

rough

sandy

shiny

glassy

dull

silky

Word Bank

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What is a rock?

A rock is a hard material from the earth. The rocks in the picture
are different sizes. Some are smooth. Some are rough.

Photo credit: Kenneth Keifer/Shutterstock

Multiple Choice

What are the 3 major types of rocks?

• Igneous, Metamorphic, Sedimentary
• Metamorphic, Igneous, Cementation
• Brown, Red, Gray
• Streak, Hardness, Breakage

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How can you describe rocks?

This rock has a smooth texture.
It is round.

This rock has a rough texture.
It is not round.

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Rocks that are the same

Sort the rocks two different ways

color

texture

rocks

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Rocks are nonliving solid material made of different minerals. Rocks come in
all shapes and sizes. Rocks can be described and named according to color,
texture, hardness, and size. Rocks can be described as being rough or
smooth, large, or small. Rocks that are really huge are called boulders. Rocks
that are smaller may be called pebbles or gravel.

What are some ways to describe rocks?

Size

Color

Hardness

Texture

Small

Gray

Firm

Hard

Smooth

Big

Large

Orange

Brown

Firm

Hard

Rough

Sandy

Pebbles

Boulder

Luster describes how the surface of the rock reflects light. It can be shiny
(metallic), glassy, dull, or silky.

How can you describe a rock’s luster?

Pyrite

Shale

Metallic Luster

Metallic minerals

Looks golden

Dull
Non-reflective

minerals

Shiny

Chalky

Dull Luster

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How are the physical properties of the sponge and the rock similar?

Porosity

Tiny spaces or holes
where liquid or air may
pass

13

Understanding Porosity In Rocks

The sponge held the most water because

it is porous, meaning it has many tiny

holes that can store water. Its open

structure allows it to absorb and retain
water effectively, similar to porous rocks

like sandstone.

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Why is porosity important?

Sedimentary Rock Layers

Sedimentary rocks often have porosity
(tiny spaces or pores) and the ability of
fluids to pass through.

These characteristics make them
ideal for storing and transmitting
natural resources like:

Oil and Natural Gas: Found trapped
within porous rocks.

Coal: A sedimentary rock that forms
from compacted plant material, used
as an energy source.

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Natural Resources Found In Rocks

These characteristics make them ideal for storing
and transmitting other natural resources like:

Groundwater: Stored in aquifers made of
sandstone or limestone.

https://www.youtube.com/watch?v=8fhMrvK0Mb8

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How do we get access to these resources?

Drilling wells and mining are common techniques for resource extraction.

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Salt Mine Train Carrying Loads of Salt

Workers in a salt mine mining and
extracting salt from underground
tunnels in the Earth.

33

All rocks are different. There are many ways to compare and sort rocks.

What are ways to classify rocks?

Size

Color

Hardness

Texture

Image by Artur Pawlak from Pixabay

7 centimeters

long
Gray

Firm

Hard

Rough outside,
smooth inside

8 centimeters

long

Transparent,

light brown

Firm

Hard

Smooth

How can you compare the size and color of two rocks below?
The flint rock and the quartz rock are about the same ______.

They are different ________.

Flint

Quartz

How can you compare the texture of the two rocks?

Multiple Choice

What does the porosity of a rock indicate?

• The color of the rock

• The weight of the rock

• The number of fossils in the rock

• The amount of space between the grains in the rock

Multiple Choice

A __________ is a natural, nonliving substance that makes up rocks. 

• Sedimentary rock
• Igneous Rock
• Mineral
• Sediment

Multiple Choice

What type of rock might contain holes from gases of quickly cooled lava? 

• sedimentary
• igneous
• metamorphic

Multiple Choice

What type of rock changes by intense heat AND pressure? 

• sedimentary
• igneous
• metamorphic

Multiple Choice

9. An aquifer is a body of rock where groundwater is stored. Humans can dig wells to use this water. What property is found in the rocks near an aquifer that allows the water to be located underground?

• They have visible crystals.
• They are porous.
• They are not shiny or metallic.
• They are not porous.

Multiple Choice

4. Porosity

• having small holes or spaces for liquid to flow through
• underground rock that contains valuable minerals
• small pieces of rock
• a natural solid material made of one or more minerals
• non-renewable energy sources that are are made from remains of decayed organisms

Multiple Choice

2. Property

• a characteristic
• underground rock that contains valuable minerals
• having small holes or spaces for liquid to flow through
• small pieces of rock
• a natural solid material made of one or more minerals

Multiple Choice

1. Rock

• a natural solid material made of one or more minerals
• underground rock that contains valuable minerals
• having small holes or spaces for liquid to flow through
• small pieces of rock
• non-renewable energy sources that are are made from remains of decayed organisms

Multiple Choice

What word describes a streak test?

• Fractured
• Powdered
• Scratched
• Liquid

Multiple Choice

The way a mineral reflects light describes which of the following?

• Cleavage
• Streak
• Luster
• Hardness

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Let’s revisit the phenomenon.

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During a field trip, the students test several rocks by
scratching them against each other. What are the students
learning from this test?

A. Which rock is the heaviest

B. The texture of the rocks

C. The hardness of the rocks

D. The luster of the rocks

Multiple Choice

The ability to resist being scratched is:

• hardness

• color

• luster

• cleavage

Multiple Choice

How a mineral reflects light is called

• cleavage

• color

• streak

• luster

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What type of scientist studies rocks?

A geologist is a scientist who studies rocks, minerals, and the Earth. They try
to understand how the Earth was formed, how it has changed over time, and
what is inside it. They also help find useful things like gold, oil, and other
natural resources.

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Why are geologists interested in studying rocks?

Geologists and engineers study sedimentary rock layers to locate
reservoirs of oil, gas, and water.