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Grades 4-6

This lesson provides students with a basis for understanding the three main classifications of rock: igneous, sedi-mentary and metamorphic. Video has been incorporated to enhance the develop-ment of mental imaging skills relative to the formation of rocks from minerals and how to accurately identify and describe each. Through interaction and hands-on experiences students will gain an under-standing of the characteristics of rocks and develop an appreciation for rock and mineral products in their environment. Videos have been selected to provide visual credibility to concepts and serve as catalysts for independent investigation.
Intrusive Igneous Rocks #114
Sedimentary Rocks #117
Metamorphic Rocks #118
Students will be able to:

(per class)

(per group of four)
(per student)
NOTE: The following activity should be conducted three or four days prior to teaching the lesson. This allows students to observe the growth of crystals and to independently increase their existing knowledge of rocks and minerals based on individual interest and research.

NOTE: Pre-prepare a crystal growing demonstration several days before the lesson is taught. To prepare, fill a one-quart canning jar with very hot tap water. Add a spoonful of washing soda (sodium carbonate) and stir with a long handled spoon until dissolved. Place the jar in a pyrex bowl, then add very hot water to within two inches of the bowl's rim. Continue adding washing soda until water becomes saturated and soda will no longer dissolve. Allow solution to cool, then pour into a second jar. Tie a large paper clip to one end of a string, then tie the other end of string around the middle of a pencil. Place pencil across top of jar permitting the clip to suspend in the solution. Crystals will form on the clip after several days.

Explain the demonstration and assign re-sponsibility for each student to observe and record their observations on a daily basis continuing until the day you plan to teach the lesson. On day the lesson is to be taught, have students bring a favorite rock to class. It should be larger than their thumb but smaller than their fist.

Read to the class or have a volunteer read Byrd Baylor's book, Everybody Needs a Rock. Allow time for students to react and discuss.

Instruct students to examine the rock they brought to class. Allow time for obser-vation. Write properties on chalkboard then ask, "Who can define the term, pro-perties?" Discuss. Ask, "What are the properties of your rock?" Allow time for responses. Say, "Compare the appearance and composition of your rock to a nearby classmate's, then be prepared to discuss likenesses and differences you observe." Allow time for completion of task. Have volunteers show rocks they compared and discuss results of their observation. Encourage interaction among class.

Engage students in discussion as you ask, "What is the most basic property all rocks have?" Elicit responses directing dis-cussion toward conclusion that all rocks in the earth's crust are made of minerals. Write minerals as a heading on chalkboard; underline term. Ask students to consider what they already know about minerals. Ask, "What characteristic of a mineral can you name?" Add characteristics of to heading on the chalk-board. Heading should now be: Charac-teristics of Minerals. List or have a student list all reasonable characteristics under the heading as they are contributed by the class. Inject the following into dis-cussion if not offered by students. Minerals are found on earth in soil, rocks and water; are classified under mineral kingdom and are a basic group of natural inorganic objects (compare to animal kingdom and plant kingdom; explain inorganic); are chemical elements or compounds; are generally solid crystals; and their chemical make-up cannot be changed.

Ask, "What are some minerals highly valued by a jeweler?" (gold, silver, diamond, ruby, etc.) List on chalkboard as named.

Display a sample of quartz, feldspar, mica and hornblende in clear view of all students. As each is identified, pass it among students for closer observation. After each student is given an opportunity to closely examine the samples have them compare and contrast. (e.g.) Each mineral was formed through crystallization; quartz is clear and glossy; feldspar is gray, white or pink; mica is dark and shiny; and hornblende is dark and appears dull. Ask, "What relationship do you see between the experiment/demon-stration observed in the classroom for the past several days and the minerals you have just examined?" Allow for dis-cussion and lead to conclusion that all the minerals were formed by the process of crystallization.

Write rock on chalkboard. Say, "Look again at the rock you brought to class. You know the process of how the basic mineral was formed. But before it became the rock you now see, it had to undergo some other process. This process determined the kind of rock it eventually became." To give students a specific re-sponsibility while viewing say, "Watch the video to discover one classification of rock. Be prepared to name the classifi-cation and tell how this kind of rock is formed."

Intrusive Igneous Rock #114
tape immediately following opening credits. Visual is an erupting volcano. PAUSE tape after visual of granite and erupting lava; audio is, "Igneous rock meaning fire formed." Allow time for students to name igneous as the classifi-cation of rock shown in the video. Ask, "Is the rock you brought to class an igneous rock?" Reserve time for interaction among students; confirm whether rocks identified as igneous are accurately classified.

Distribute a pencil and sheet of notebook paper to each student. Instruct them to list igneous as the rock-type, then write a description of how it is formed. Allow time for completion of the task. Have volunteers share their description. Elicit discussion related to the meaning of term igneous (fire formed); include that this classification or type of rock is formed inside the earth. Say, "In the next video you will see examples of igneous rocks and names of each. What would you predict some of the examples might be?" Allow students to make predictions. To give students a specific responsibility while viewing say, "Watch to find out if your prediction is correct."

RESUME tape. Video follows old photo-graphs of the earth's layers. STOP tape after visual of rocks. Allow time for students to discuss the accuracy of their predictions. Say, "Again use your note-book paper and list examples of igneous rocks as shown on the video. Review the list through student interaction and have those with incomplete lists to complete them.

Say, "Granite and marble are two igneous rocks greatly valued for their beauty and durability. What uses have you seen made of these rocks in your community or other cities you've visited?" Allow students to share their experiences which might include state buildings, museums, churches, statues, floors or stairways in public buildings, etc. Ask, "Why do you suppose you are unlikely to see marble or granite used as flooring in the average private home?" Allow for responses.

Write the following on chalkboard, then have students figure total cost. A 12" x 12" square of marble flooring is priced at $15.00 each; The floor to be finished as marble measures 15 feet x 20 feet; The mason's fee for installing the marble is $4.25 per square foot; What is the total cost of the floor? (15' x 20' = 300 sq. ft.; 300 sq. ft. x $15.00 = $4,500; 300 sq.ft. x $4.25 = $1,275; $4,500 + $1,275 = $5,775) Although the preceding cost/fees are fictional, have students decide a reason-able cost for quality carpeting and compare with the cost for marble. Ask, "Is it reasonable that the average household could not afford this?" Allow students to respond.

Say, "Not all rock found on earth is as hard as marble or granite. Two basic factors play the greatest roles in deter-mining characteristics of rocks. What do you believe these main factors are?" Allow time for students to discuss, then validate by saying, "Minerals and the process which transformed them into rock are determining factors."

To give students a specific responsibility while viewing say, "As you watch the next video be prepared to name another classification of rock and tell how it is formed."

Sedimentary Rock #117
tape immediately following opening credits. STOP tape following visual of chalk mountain; audio is explanation of how chalk is formed. Ask, "What name is given to the classification of rock you saw on this video?" (sedimentary) Have students write Sedimentary rock on their notebook paper, then use their own terminology to define and describe how this classification is formed. Allow time for students to discuss results of the previous task; correct any misconceptions. If students do not include the following, inject into or draw-out through questioning as may be appropriate: Erosion causes rocks and minerals to break up into smaller pieces generally referred to by scientists as sediments. Mud, sand, clay and tiny deposits of minerals are carried by water, wind and sometimes shifting ice. These are often deposited in river beds and eventually some continue moving until they are deposited in oceans and seas. Whenever the sediments arrive at a stable area which no longer promotes movement, the sediment accumulates in layers. As sediment reaches any of these locations, it is deposited on top of the previous sediment that was deposited at an earlier time. Over hundreds and thousands of years the sediment particles become pressed together as layers by the weight of additional sediments deposited on top of them. Dissolved minerals in the water often act as cement and seal the particles together. Eventually, this hardens to form new rock.

Ask, "Who has found a rock sometime that contained a small plant or animal fossil?" Allow students to share experiences. Encourage them to draw on knowledge of how sedimentary rock is formed and explain how they believe these organic forms eventually became inorganic through fossilization. Discuss organic and inorganic. Assist and correct misconceptions as needed.

Say, "In the future when you see natural rock formations with bands or layering, what will this characteristic tell you about how the rock was formed?" Allow for responses. Ask, "What type physical features might you expect the land to have if you are traveling an interstate highway and see a wall of sedimentary rock on one or both sides of the road?" (hills or mountains which had to be blasted through to make way for the road)

To give students a specific responsibility while viewing say, "As you watch the next video you will learn the third classifi-cation of rocks. Be prepared to name the classification and describe how these rocks are formed."

Metamorphic Rock #118
tape following opening credits. PAUSE tape on visual of cloud formation; audio is, "...tens of thousands of kilometers beneath the earth's surface." Allow time for students to name metamor-phic as the third type of rock. Say, "Write metamorphic on your notebook paper and use your own terms to describe how this classification of rock is formed." Allow time for the task to be completed, then encourage volunteers to share their definition. List characteristics of metamorphic rock on chalkboard.

Ask, "What is your theory about how mountains are built?" Allow students to share their theories. To give students a specific responsibility while viewing say, "The last video explains how mountains are formed; as you watch, test your theory for accuracy." FAST FORWARD tape to visual of mountain range; audio is, "During mountain building..." STOP tape with visual of a male; audio is, "...wide range of temperatures and pressures possible in the earth." Allow time for students to discuss whether their theories on how mountains are formed were or were not accurate. Correct any miscon-ceptions during this interactive period. Ask if anyone brought a rock they believe is metamorphic. Allow other students to share their opinions about the classifi-cation. Confirm or correct any miscon-ceptions shared by students.
Create an observation center where students can examine results of the crystal growing demonstration at close range. Display the string of new crystal formations on a paper towel and provide a hand lens for close up observation.

Divide class into groups of four students each. Distribute a few grains of salt placed on a paper towel, a hand lens and a box of colored pencils to each group. Give each student a sheet of manila paper. Say, "Use half of your paper to illustrate the formation pattern of the salt crystals. Use the other half to illustrate the pattern of crystals formed as a result of the washing soda crystal demonstration you have observed for the past several days." Have groups alternate going to the observation center as other groups examine and illustrate salt crystals provided each group. After the tasks have been completed by all groups, allow time for discussion and comparing the crystal formations. Display illustrations in the classroom.

Set up five numbered stations to facilitate tasks to be accomplished using the activity sheet. place four metric rulers in station one; place one balance scale in station two; place one penny and one nail in station three; place six tablespoonfuls vinegar in a small jar and one small rubber-bulb syringe in station four; and one three pound plastic margarine tub three-quarters filled with water in station five. Distribute a copy of the activity sheet to each student. Say, "Use the rock you brought to class and complete the activity sheet to determine how your rock differs from those brought by others. Do this as you move through the stations." Point out stations and discuss tasks to be accomplished at each.

Select a group to begin at station one and complete the task assigned. Have them repeat the process for stations two through five then return to their seats. Instruct another group to begin at an appropriate time; continue until each group has moved through the stations. After all groups have completed the tasks, allow students to share what they discovered about their rock. Compare and contrast results. If space is available, display each rock and its appropriate activity sheet near the five stations. Allow interested students to check individual rocks and activity sheets for accuracy at a later time.

Plan a field trip to the Children's Museum in your community. Request the service of a staff member to make a presentation on rocks and their formations. Have students write notes of appreciation following the trip.
Creative Writing
Display a geode; a nodule of stone having a cavity lined with crystals or mineral matter. Encourage students to use their imaginations and write a creative story on how the geode was formed. Explain the story is to be fictional, thus their imaginations can "run wild."

Have students draw illustrations of their own jewelry designs which include use of precious metals and stones. Designs could include a ring, stickpin, crown, bracelet, brooch, etc. Use cut-out designs and allow interested students to create a bulletin board for displaying them.

Set up an independent learning center; in-clude several books on rock identification. Display a collection of rocks and minerals. Allow interested students to use the resources for identifying the rocks and minerals.

Make a Venn Diagram using two yarn circles on the classroom floor or a table. Have students place the rock they brought along with those of their classmates, in a pile. Work together as cooperative groups or as a class as rocks are sorted by color, shape, size, weight, etc.

Master Teachers: Anna Sedoris and Jaci Stewart

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