Rocks and Minerals Mission Plan
Galaxy Explorers will be able to complete the following upon completion of this mission:
1. Mission Team members will be able to verbally state the three different kinds of rocks
and how they are formed.
2. Mission Team members will be able to define a rock and a mineral.
3. Mission Team members will be able to describe how rocks and minerals affect their lives.
Mission Team Leader’s Notes. Mission Team members must do a little preparation by having
team members collect rocks and minerals from around their schoolyard and home. These objects
can be brought to the mission meeting and analyzed. Alternatively, collecting and identifying
rocks can be done as a field trip. A filed trip also illustrates the need and process for human and
robotic exploration of planets.
Required Materials:
Igneous rock (granite)
metamorphic rock (quartz)
sedimentary rock (sandstone)
a sheet of white tile (back will be used)
DISCUSSION
Today we are going to discuss geology, the study of the earth. How do your pencils relate to
geology? What about this piece of chalk? The pencils you are holding are made of graphite,
which is a mineral. The chalk I'm holding is a type of limestone. When I write with this chalk I
might be writing with shells of ancient animals. Geology is not only important for items we use,
but studying rocks and minerals can provide information about the earth's past.
What is geology the study of? It is the study of the earth's history, composition, and the changes
that it undergoes. Hold up an apple in front of the class. If this apple is our earth, does anyone
know what the layers of the apple would represent? Cut the apple exposing the flesh and core.
What does the skin of the apple represent? The crust. The fleshy part of the apple represents the
mantle, and the pit with the seeds represents the core. If we are drilling into our apple (the earth),
how far would you be able to drill into it? You would not make it past the skin. We can currently
drill only a few miles into the crust, but cannot sample rocks from the mantle directly. Now, let's
think a little differently about rocks that are not on the earth. Approximately 19,000 meteorites
fall from space each year. However, geologists are only able to study about ten a year due to the
fact that most fall into the ocean and deserts around the earth, or they burn up in the earth's
atmosphere upon entering it.
"Who can tell me what a rock is? Write all the important words and definitions on the
chalkboard. A rock is usually made up of one or more minerals. Who knows what a mineral is?
Minerals are pure, solid (natural) materials found in the earth's crust. They are inorganic or
lifeless and are made up of elements, which cannot be broken down.
Rocks are formed in different ways by which we can categorize them. Does anyone know the
three types of rocks? Who can name one?
Igneous rocks. How is an igneous rock formed? (Show an example of an igneous rock).
This rock was formed by tremendous heat generated by a volcano. What is hot lava called when
it is still under ground? Magma. There are two types of igneous rocks: intrusive, which are rocks
that have solidified within the earth's crust and only appear at the surface when other rocks have
eroded away, and extrusive, which are formed when magma erupts from a volcano as lava, then
cools at the earth's surface.
What is another type of rock?
Sedimentary rocks. Who can tell me how a sedimentary rock is formed? First, let's look at the
word. What is sediment? Sediment can be sand, mud or other small particles. Sedimentary rock
is formed when sediments are bound together under intense pressure." Pass around a sedimentary
rock (sandstone). "Sedimentary rocks are the most common rocks on the earth." (Mission Team
Leader can also mention the three types of sedimentary rocks: clastic, from fragmented rocks;
chemical, from chemical precipitates; and organic, derived from ancient living matter.)
What is the third type of rock?"
Metamorphic. (Show an example of a metamorphic rock (quartz).
How is a metamorphic rock formed? A metamorphic rock is formed when one rock changes its
form due to heat, pressure, or water. Some examples of metamorphic rocks are marble from
limestone, gneiss from granite, and slate from shale. Now we know the three types of rocks.
Again, what makes up a rock? Minerals. What are minerals used for? What do you think glass is
made up of? Did you know minerals are in your toothpaste? Minerals are all around us.
Minerals can be identified by their properties such as color, luster, magnetism, and hardness.
When minerals break, some split along one or more planes. This is called cleavage or fracturing.
Show the mica specimen and how it fractures in sheets. Today we are going to sample some
minerals using the same tests that geologists use.”
Activity
"We are now going to be planetary geologists, people who study the history of the earth – or
other planets -- and their rocks and minerals. Minerals have many properties. By learning and
studying the properties of rocks and minerals, we can identify them."
Discussion Questions: "Why did we do this activity? What is so important about identifying
minerals? If we know the properties of certain minerals then we can know how to use them,
where they came from and also develop new uses. For example, the Notre Dame Cathedral was
built with limestone and the Empire State building was made with granite".
Rock Identification
Have mission Team members categorize rocks according to pictures below.
Mineral Identification
1. Divide the Mission Team into groups of three – five members.
2. Give each group a worksheet, tile, file, penny, magnet, piece of glass, steel nail or small knife,
and three different minerals.
"Each group is going to get a variety of minerals. We are going to figure out what each of those
minerals are. Choose one mineral to work with at a time. Determine the color of the mineral you
are working with. Next, streak the mineral on the back of a white tile and write down the color of
the streak. Decide if the mineral is metallic, glassy or earthy. This property is known as the
mineral's luster. Metallic would be shiny like a quarter.
•
Black - Graphite
•
Black - Pryite
•
Black - Magnetite
•
Black - Chalcopyrite
•
Gray - Galena
•
Limonite - Yellow-brown
•
Hematite - Red-brown
After determining color, you will do a hardness test. Determine if the mineral is harder than your
fingernail, a penny, a piece of glass or the steel file. For example, talc is the softest mineral and a
diamond, from coal, is the hardest. When you have finished doing these tests on all the minerals
you will be able to identify each mineral."
IGNEOUS
SEDIMENTARY
METAMORPHIC
Has numerous tiny holes
VERY hard to break. Breaks
into jagged chunks when
broken (called fractures)
Has multiple layers
EASY to break apart. Splits
into smooth, flat slices.
(called cleavage)
Reacts (fizzes) when exposed
to a few drops of lesson juice
or vinegar
Has swirled pattern
HARD to break apart. Breaks
into jagged chunks when
broken (called fractures)
Has dark and light speckles or
large crystals
Shiny
This property is the measure of a mineral's ability to resist scratcing or abrasion. It is represented
by a number between 1 and 10, according to a reference set of minerals. Known as the Moh's
scale after the mineralogist Friederich Moh, 1 represents the softest (Talc) while 10 is the hardest
(Diamond). Each mineral in the list can scratch any other with a lower number but can only be
scratched by those with a higher number. The reference set is as follows:
Moh's Scale of Hardness
Hardness
Test Procedure
Mineral
1 Leaves greasy flakes on fingers
Talc
2 Scratched by fingernail
Gypsum
3 Scratched by penny
Calcite
4 Scratched easily by knife
Fluorite
5 Not scratched easily by knife
Apatite
6 Scratched by file
Orthoclase
7 Scratches glass easily
Quartz
8 Scratches glass easily
Topaz
9 Scratches glass easily
Corundum
10 Scratches all other materials
Diamond