Hobbies And Interests
Identification
Begin by showing your students different rocks. Pass them around, and ask students to talk about their characteristics, such as color, hardness, smoothness and weight. Explain the characteristics that geologists use to identify types of rocks, showing them examples of such things as hardness tests.
Next, show students at least two rocks from each class of rocks: sedimentary, igneous and metamorphic. If you can't obtain rocks, use pictures. Ask students to make educated guesses about what type of rock each specimen is.
When they understand how to identify them, provide a list of rocks with various characteristics and set up 10 to 12 stations with different rocks. Ask them to make observations and try to identify what type each one is.
Making Rocks
To help your class understand how rocks are created, try constructing different types of "rocks." You can make "igneous fudge," filled with marshmallows, mint pieces or bits of toffee to show how igneous rocks solidify. Or you can heat up a certain chemical or substance and pour part if it on a plate that sits in a freezer and the other part on a plate that sits at room temperature, then let your students observe the differences.
Have students make their own sedimentary rocks by putting different colored layers of plaster mixed with different "fossils" in a milk carton and drawing the resultant "rock." You also could have your students make rock candy to explore how crystallization works.
Rock Hunters
Take students on an exploratory rock hunt to see what kind of rocks they can find on the playground, or send them home to search for rocks in their yard with their parents. Have them bring the rocks back to class and examine them to identify what type of rocks they found. Have students record their findings with detailed drawings and observations.
Finally, ask students to combine their rocks for a classroom exhibit. Challenge them to decide how the rock collection should be organized and displayed, ensuring that they provide a little information about each rock and group in the collection.
Rock Cycle
All of the earth's rock undergoes a cycle of modification by the processes of metamorphism, melting, crystallization, lithification and weathering; this is known as the rock cycle. Explain the processes that transform rocks, and let students explore this transformation with sugar cubes.
Have them examine a sugar cube with a magnifying glass, making detailed observations, then have them crush the cubes into a powder, observing the cubes again. Finally, have them heat the sugar in a spoon or a boat of aluminum foil, then let it cool and break it into pieces.
Have the students correlate each step to a step in the rock cycle and record their observations, noting similarities and differences between this cycle and the real rock cycle. This also works with crayon shavings.