Classifying Rocks

Designed by: M.B. Wright, Satchel Ford Elementary School

Grade: Third      Subject: Science

Core Curriculum Objective (s): Describe Earth materials (rocks, minerals, soil, and fossils) by their physical properties.

Overview: Using process skills students will classify Earth materials by their physical characteristics. Students will use rocks, minerals, soil, and fossils to classify and to find similar and different characteristics of each. Students will also use the computer to identify some rocks and minerals and describe how they are alike and different.

Focus/ Essential Question(s): How are some rocks, minerals, soils, and fossils alike and different, and how can you classify them?

Time Frame: Three Fifty minute lessons

Resource material: 
Samples of different types of rocks 
Soil samples 
Fossil samples 
Mineral samples 
Zip-Lock bags 
Averkey 
Data Record Sheet 

Books: 
The Audubon Society Field Guide to North America Rocks and Minerals Author: Charles W. Chesterman 

The Big Guide to All the Minerals Author: Frank Murray, Jean Barilla 

The Encyclopedia of Gemstones and Minerals Author: Martin Holden 

Web Sites: 
www.library.thinkquest.org/joo2744/adlm-album2.html www.galaxy.einet.net/images/gems/ameths.gif 
www.gemsrocks.com/a/gm/500.html

Culminating Assessment: Students will work in groups to classify different rocks, and minerals. They need to come up with a clear way that all of the given materials can be classified into two groups. Students will then classify soil samples and fossils in groups. Students will make observations and inferences about these materials and keep a record of the observations and inferences using the data record sheet.

Rubric for Describing Rocks, Minerals, Soil, and Fossil Samples

Instructional Activities: 

Activity One: Ask students to tell you their prior knowledge of observations (they should come up with the five senses). People make observations by using their senses and that is what they will be doing today (excluding taste). Tell students they are going to be given a bag full of materials that they are to make some observations about. Hand out bags of rocks to the small groups and ask them to talk together and come up with some observations about these materials. Hand out observation sheet, and have students record some observations made about the rocks. Let students share aloud some of their observations. Have one group go to the computer and use one of the sites from the list above (under resources) and let them make observations using the computer. Explain what it means to make an inference to the students, and how observations and inferences are different (inferences would be where they think the rock came from and why, or why they think the rock has a hole on one side and why). Have students make some inferences about their rocks and let them tell you aloud before writing on the recording sheet. Once they have this concept let them make some inferences as a group and have them record these on the recording sheet. Now that the students have their observations and inferences written down, discuss what it means to classify (put in groups according to physical characteristics). Have each group classify their rocks and put them in groups according to physical characteristics, remind them that these groups cannot be grouped by opinion statements. Now have each group of students walk around the room to observe the other classification techniques of their peers to see who can guess how the other groups classified the rock samples. Once students have observed each other's samples and they have seen how the other groups classified the rocks discuss other ways they could have classified the rocks. Ask students to tell you the difference between observation and inferences and ask them what it means to classify. Tell students they will do the same thing in the next lesson using another type of material. 

Activity Two: Again students work in groups and they will observe and make inferences about minerals. Remind students of the difference between observation and inferences. Students will get samples of different minerals and have them observe and share with the class. Then have them make inferences and share with the class. After several correct observations and inferences have been made, students write down different observations and inferences on the recording sheet. During this time have one group of students use the internet site: www.gemsrocks.com to make observations, and inferences of minerals from the computer. Once all students have completed the recording sheet, discuss ways they can classify the minerals. Have students classify the minerals into two different groups, then have them classify those two groups again. The group of students at the computer can come up with ways to classify by looking at the different minerals. Bring students together and discuss the different ways they classified. Tell students tomorrow they will continue to classify, observe and make inferences about other Earth materials. 

Activity Three: Ask students what the difference between observation and inference is. Review the two Earth materials that they have observed and classified. Ask them to tell you what kinds of observations they might make about soil and fossils. Hand out samples of soil and have students make observations of soil, and have them as a group, write down these observations on the recording sheet. Have students make inferences about soil (what kinds of things might live in it, how did it become soil). Let students share what they observed and inferred about soil with the class. Students will do the same thing using fossils now. Let them share their prior knowledge of fossils, then hand them samples and have them observe and infer about the fossils. Again one group can go the computer and use one of the above sites and do their recording using the computer. Students should have a good idea by this time about observation and inferences, as they share aloud ask questions of them such as where could this have come from, and why do you think the color is darker than the rest. After all students have finished activities have them share some things they learned about rocks, mineral, sand, and fossils. Take up all recording sheets, and after they have been assessed, hand them on the wall for others to observe.

Data Recording Sheet