Exploring Rocks: Rock Identification and The Rock Cycle

Goal #1—Students will analyze the differences between rocks.
Goal #2—Students will improve observation skills and share their findings with classmates.
Concept #1—Students will be able to tell the difference between a rock and a mineral.
Concept #2—Students will able to describe ways that rocks change form one form to another.
Concept #3—Students will be introduced to the Rock Cycle and the types of rocks associated with this cycle.
Vocabulary Words—rock, mineral, Igneous, Sedimentary, and Metamorphic

This lesson is taken from a second grade FOSS lesson. The part of the lesson where the rock cycle is developed is a part added to enhance the lesson. The class size for this activity works with numbers ranging from 20-25 students. Since I teach in a small K-12 public school I can borrow needed rock materials and rock kits from my high school science department in addition to the rocks that come with the FOSS kit. Most of the observation activities work best when students work in small groups and share the materials. Group sizes of 2-4 work best depending on the number of materials you have. After the students have had appropriate observation time they will then participate in teacher directed discussion and short lecture time. During this teacher directed time the vocabulary will be introduced and developed. This lesson will probably take about five days. Each day should take about 45 minutes. The teacher will need a wide variety of rocks to share with the students and they should also have small magnifiers to help look closer at the rocks. Students should have a good background in making and recording observations. This will be helpful in making better observations.

The main part of this activity will be to teach students to make careful observations about unknown rocks, record their findings, and then use these observation skills to learn about the different rocks that are part of the rock cycle. To start the lesson the students will be given three rocks that they are to study carefully and then record some basic observations in their notebooks. The three rocks that I use are basalt, tuff, and scoria. Following this activity the students will then wash their rocks in water and record further observations in their notebooks. The students will then be given some other rocks and then be asked to make the same observations and do the same tests. The students will then take all of their rocks and sort them based on categories that they have chosen. Once students have made all of their observations they should begin to develop a basic understanding about rocks and begin to know that are a part of the earth. At this point I will share with students that their first three original rocks are volcanic rocks, also known as Metamorphic Rocks. At this point I would begin to explain to students that all rocks are part of something called the Rock Cycle. At this time the students will also be taught the main difference between rocks and minerals. I would then present students with a simple diagram of the rock cycle. I would then continue to share with students some different types of rocks from this cycle, their characteristics, and where some may be found here in Minnesota. As these different rocks are discussed I will have the students make drawings of at least one kind each rock and write a basic description. To conclude this activity volunteers will be asked to pick a rock and describe it using the ideas that they have learned.

To best complete this lesson you need to start by having good supply of igneous, metamorphic, and sedimentary rocks. When using FOSS kits with this lesson they do come with a good supply of rock material. When doing this activity in a regular activity classroom you should be prepared for it to become somewhat messy. If you plan ways to store and organize the rocks you should have no problem. The students will love observing rocks and they will be ready to tell you all about the rocks that they have found at home. Student motivation will not be a problem. This will be my first year teaching the rock cycle to students so I will interested to see how well they understand and can use the rock cycle. However, at the second grade level I will not be worried about students fully mastering the rock cycle, but instead I will be mostly concerned about them making and recording useful observations.

Group Activity: Students will be placed in small groups. They will then be given three unknown rocks and asked to determine where they may fit into the rock cycle. The students will use their notes to help them describe their rocks. The groups will then make a poster of their rocks to share with the class. For record purposes the students will then turn in their notebooks and they will be graded on the posters that they make.

2.III.A.1 - Identifying Basic Earth Materials