By the Institute for Crustal Studies
Back to Index
In this hour exercise the students will explore rocks and minerals. Specifically they will study the rock cycle, the three main rock types (igneous, sedimentary, and metamorphic),
common minerals, and the connection between minerals and rocks.
This will be done by a rock/mineral sorting exercise and an activity of having the students stand up and act out the rock cycle. This will best work with 15 or less students
- Grade Level
- Subjects Covered
- Igneous, Metamorphic, and Sedimentary rocks
- Rock Cycle
- Scientific Observation
One hour or more
- Large examples of igneous, metamorphic, and sedimentary rocks to show the class.
- One small example of quartz, calcite, feldspar, mica, hornblende, and olivine
all put into a Mineral Bag (for organization purposes). You will need one Mineral Bag per student,
as they will use this for the sorting exercise, and one Mineral Bag for yourself as an example.
- Blank paper and sheets for sorting exercise
- Large enough space for rock cycle exercise ( about 12 by 12 feet).
- One quiz per 3-4 students
Unless noted, all definitions from the USGS website
- Igneous Rocks: Igneous rocks (from the Greek word for fire) form when hot, molten rocks and minerals (magma)
crystallize and solidify.
- Magma: Molten minerals or rocks that exist under the soil and sometimes come out onto the surface in sites like volcanoes.
- Metamorphic Rocks: Metamorphic rocks started out as some other type of rock, but have been dramatically changed from their original igneous, sedimentary, or earlier metamorphic form.
Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot, mineral-rich fluids or some combination of these factors.
- Mineral: The technical definition of a mineral is a naturally occurring, inorganic, homogeneous solid with a definite chemical
composition and an ordered atomic arrangement. In more general terms, a mineral is a substance that is (1) made of a single element
like gold (Au) or a compound of elements like salt (NaCl) and (or) (2) a building block of rock (for example, granite is composed primarily of the minerals quartz and feldspar).
Definition from this USGS PDF on minerals
- Rock: Rocks are made up mostly of different kinds of minerals,
or broken pieces of crystals, or broken pieces of rocks. Some rocks are made of the shells of once-living animals, or of compressed pieces of plants.
- Rock Cycle: The cycle in which rocks transform between igneous, sedimentary,
and metamorphic states via the processes of the earth such as compression, heat, and natural acids.
- Sedimentary Rocks: Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They
form from deposits that accumulate on the Earth's surface. Sedimentary rocks often have distinctive layering or bedding.
- 0-5 Minutes
Start with the students at their desks and the materials covered so there are no distractions.
Introduce yourself and then ask the students "How are you doing? HowÕs school? Do you like science? Why? This will be a good
invitation to get the students talking and involved.
- 5- 17.5 Minutes
Inform the students that today we will be talking about rocks and minerals. You ought to tell them what they are, and why they are important to people. One good way to start is to ask,
"Has anyone here ever eaten a rock or mineral?" You can inform them that of course they have when eating things like fruits, vegetables, meat, cereals and salt
(See this Geological Society Website for more information)..
Then ask "Besides small amounts for eating, are minerals and rocks useful? How?" Hopefully this will get more discussion going you can mention they are used in tons of ways such as creating metals,
making roads, glass, chalkboards, decoration, and of course they make up the entire earth itself. "So we know rocks are useful and all around us, but can any one tell me what a rock or mineral actually is?"
This will likely get no response, but it is good to get them thinking. Then do a little bit of lecturing on what minerals and rocks are.
Discuss the fact they come in all different shapes, colors, and properties and that is how they can be told apart. Also discuss the three types of rocks
and what their properties are. Go on to the sorting exercise.
- 17.5-32.5 Minutes
This portion addresses the California State Science Standard that students be able to use a "table of diagnostic properties"(4:4:b).
Hand each student a blank sheet of paper and one Mineral Bag (these contain all the necessary minerals. The students will take
all six of their rocks and put them in a pile at the top of their blank page held lengthwise (see figure 1 ). Then
we will use the diagnostic table to slowly separate them by different features. First have them separate the rocks into two groups, as showing
in figure 1, of "Rough and Smooth." Then have them separate the rock/minerals into "Shiny or Dull." Finally have the students now separate it
by color. You may want to ask things like "in what ways can we separate the rocks" in the beginning to get them thinking and in a way let
them design the exercise. Also mention that there are even more ways to classify rocks such as density, scratch examples, and chemical
reactions. Now play a game where you describe what the rock looks like and tell them what name it is so they can write it below the rock
on their paper. For example, "We are looking for the smooth, shiny, pink mineral. Everyone find it? Ok under that write Quartz." Maybe
tell them a cool fact about each one. Have them clean up by putting the rocks back in the bags and collecting the paper for recycling.
- 32.5-50 Minutes
Now we will address the rock cycle. Have the student come into the clear space you have provided. Tell them that now we are going to do a
special performance called the "Rock Walk." Split them into groups of 2:2:2:4:4. Separate the groups of two into a triangle shape with each
group making a point (Figure 3). Then assign them group names of "Volcano," "Ocean," and "Mountains." Then separate the groups of four and
say that they are "Minerals1" and "Minerals2." Put each of the members of the group in a different body position to symbolize that they are
different minerals with different properties (Figure 4).
Tell the students that this is the beginning of the rock cycle, since all rocks
are made of minerals or other rocks. Describe an outline of the rock cycle, and that now they will act out the rock cycle. Have group Mineral1
go to the Volcano. Explain that here the minerals are superheated and molded together. Have the Volcano group link the arms of the Mineral1
group together to form a new rock made of many minerals (Figure 5). Then have the Mineral1 group go stand between the Volcano and Ocean. Now
have Mineral2 group go through the Volcano, and encourage Volcano to arrange them in a different manner then the others. Have Mineral2 go
stand with Mineral1 and explain that these are igneous rocks. They have been made molten by magma and then fused together in cooling.
have both groups go to Ocean. Have Ocean pluck them apart, intermix the groups, and put them in "layers" (Figure 6) by lining them up facing
he same way. Make sure they keep their arm positions! Have the two new rocks go and stand between Ocean and Mountains and explain why these
are now sedimentary rocks.
Next have the students go to the Mountains. Here explain that the pressures and heat of being deep underground
cause metamorphic rocks to be formed. Have the Mineral groups stay as sedimentary rocks, but have then have Mountain change their arms
positions and move the line into different shapes (Figure 7). We see that the sedimentary rock has changed into a metamorphic rock. Explain
that this is the rock cycle, but ask them why it is called a "cycle?" The answer is that it must go round and round, and so do that! Have both
rocks go back to Volcano, then back to Mountain, then to Ocean, to show that the cycle can go different ways. These times you can do it faster
with less explanation so itÕs quick and fun for the students. If you have time have them go back and forth between two stations to show that
a mini rock cycle could even happen. Conclude with a last overview of the rock cycle while the students are back in their seats.
- 50-60 Minutes
This is the time for the assessment and wrap up. Form them into groups of three or four and hand out the Quiz Sheets. Let them work on it together for five minutes
and then go over the answers with the class. See what the students answered and why. You can learn what topics you need to emphasis next time.
California State Science Standards Covered
All vocab definitions are provided by the US Geological Survey Website
Notes and Comments
Please comment here if you have preformed this lesson plan and have found ways to improve it, effective examples, new ideas for a lesson, etc.