Rock Collecting

Suggested Grades



Students will practice classifying rocks in the categories sedimentary, igneous, and metamorphic.


  • plastic jars that students can easily carry with them
  • 4 large pieces of paper per student
  • markers
  • examples of sedimentary, igneous, and metamorphic rocks (real, pictures in books, and/or pictures from internet: see below)


  • Explain to students the major classification system for rocks.
    Sedimentary: Rocks formed by the layering of sediment.
    Igneous Rocks: Rocks produced by the crystallization of molten lava.
    Metamorphic Rocks:Rocks originating from a previously existing rock that is subjected to high temperature (but not enough to melt it) high pressure, and chemicals.
    Show them examples of these rocks.
  • Hand out a jar/pail to each student. Ask students to collect as many different types of rocks that they can. (can search outside of school time, or set aside times during school). Give students about two weeks.
  • At the end of this time have students bring their collections to school.
  • Hand out 4 large pieces of paper to each student and have them label them sedimentary rocks, igneous rocks, metamorphic rocks, and not sure.
  • Explain the different categories again and display the examples.
  • Ask students to try to categorize all of the rocks that they collected.
  • When done, have the class view their classmates’ collections and help each other with the rocks that others were not able to classify.
  • Have each student count the number of rocks that they collected in each category. On small pieces of paper, write down the number rocks collected for each category. Tape these labels on the side of the jar.
  • Let students keep their jars as permanent collections.
  • Extension: Have student use rock classification guidebooks or those on the sites below to identify the names of some of rocks they found.