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Using a Magnifier
Name
Date
Vocabulary
STUDENT RESOURCE 1.1
INFORMATION SHEET
hardness How hard a mineral is
compared to other minerals.
A scratch test shows the
hardness of a mineral.
property Something that can
be observed, that can be used
to describe or sort objects.
2. Ask students the following questions: What is a rock?
What do rocks feel like? What color are they? How
can you tell an object is a rock? (Accept all answers.)
rock Solid Earth material made
of minerals.
Copyright © Houghton Mifflin Company. All Rights Reserved.
mineral A solid that is found
in nature, was not made by
anything alive, and is made of
only one kind of material.
1. Make copies of Student Resource 1.1, Vocabulary, and
distribute to students. Discuss the definitions with
students as the terms come up throughout the section.
3. Tell students they will use magnifiers to observe rocks.
Give each student a magnifier. Have students hold the
magnifier close to a pencil and pull it back slowly until
the object is clear (focused). Observe and help students.
Ask: Which lens makes objects appear biggest?
(smallest lens) Let students practice using a magnifier to
look at fingertips, clothing, shoes, Velcro, carpet, newsprint, and so on. Tell students never to touch an object
with the magnifier, as the magnifier will get scratched.
Have them return magnifiers to bags when finished, to
prevent scratching.
10 • ROCKS, SOIL, AND FOSSILS • SECTION 1 WHAT IS A ROCK?
Student Resource 1.1 (p. 10)
Observing and Sorting
Rocks
20 minutes
Pairs
Objectives
• Students sort the rocks from the minerals in a group of samples.
• Students examine rock samples and classify by two properties.
Materials
For each pair
1
magnifier
1 set minerals: calcite,
feldspar, graphite, talc
1
paper cup
1 set rocks: conglomerate,
gneiss, granite, pumice
4 • EXPERIENCE SCIENCE
1
tray
•
*water
*Not included in kit
Inquiry Focus
• Classify
Observing and Sorting Rocks (continued)
Teaching Tip
Step 1: Many rocks have such
fine grains that you cannot see
separate minerals without a
special microscope. Pumice is one
such rock, which is why it is being
set aside at first.
Heavy
pumice
granite
conglomerate
A One way to sort rocks by
properties
Minerals
calcite
feldspar
quartz
talc
3. Students sort rocks by two properties.
Give each group a pumice sample. Tell students that
pumice is a type of rock too, even though you cannot
see the minerals in it. Have students sort all the rocks
by one property—for example, by color, texture, or
how heavy it feels. Discuss how they sorted the rocks.
Then have students choose a group with more than one
sample and sort by a second property.
ROCKS
Speckled
2. Students identify samples as rocks or minerals.
Tell students that rocks are solid Earth materials that
are a mixture of minerals. A mineral is a solid found in
nature, that was not formed by anything alive, and that
is made of only one kind of material. Walk around the
room and make sure students have placed each sample
in the right group. Say the names of the rocks and
minerals and write them in a chart on the board. Then
collect the mineral samples and return them to the kit.
Rocks
conglomerate
gneiss
granite
[pumice]
A Observe samples with a
magnifier.
Lightweight
1. Students sort samples.
Divide the class into groups of two. Give each group a
tray of rock and mineral samples mixed together. (Do
not include pumice at this point.) Ask students to examine the samples with a magnifier and sort them into
two groups: those that look like they are made of one
kind of material and those that look like they are made
of more than one kind of material.
Striped
4. Pumice: a rock that floats
Distribute a cup of water to each group. Ask students to
predict what will happen if they place each rock in the
cup of water. Have them try it. (The pumice floats; all
the others sink.) Point out that pumice is full of holes.
The air in the holes makes it light enough to float in
water. Pumice is the only type of rock that floats.
gneiss
Assessment
Have a student hide a rock in his or her hand and
list three of its properties. Have others guess which rock
the student is hiding.
SECTION 1 WHAT IS A ROCK? • 5
Homework
My Rock Collection
Name
Date
My Rock Collection
STUDENT RESOURCE 1.2
HOMEWORK SHEET
Copyright © Houghton Mifflin Company. All Rights Reserved.
Search your yard, playground, or neighborhood for
two different rocks. Then fill in the chart.
Rock 1
Draw a picture.
Rock 2
Draw a picture.
List two properties.
1.
List two properties.
1.
2.
2.
How many different minerals
How many different minerals
can you see?
can you see?
Make copies of Student Resource 1.2 My Rock Collection
and distribute to students. Give students several days to
complete the activity. Then have them bring their rock collection, the completed sheet, and any rock pets they made
to school to share with the class.
Pet Rocks Only do this if you want to. Collect
extra rocks. Smooth rocks work best. Glue them
together and paint them to make pet rocks.
ROCKS, SOIL, AND FOSSILS • SECTION 1 WHAT IS A ROCK? • 11
Student Resource Page 1.2 (p. 11)
Share with Your Students
Telling Minerals Apart
Ask students to imagine two plants on a windowsill. The
plants look the same, but one is real and the other is
artificial. Ask: How could you find out which plant
is which? (Students might suggest touching the plants,
smelling the plants, trying to break off a leaf, and so on.)
Explain that there are many minerals, and some look alike.
Scientists must use more than appearance to tell minerals
apart. They must also test mineral properties.
6 • EXPERIENCE SCIENCE