Unique Classy Rocks

By Susan M. Frack

This activity will introduce the three types of rocks in a 'tasty' way.

For each group of 3-4 students you will need a basket containing:

  • 1/2 c peanut butter
  • 12 crackers
  • knife
  • 12 pieces of saltwater taffy
  • 8 pieces of waxed paper
  • 4 paper towels
  • 1/2 c melted almond bark/similar candy candy molds--available at craft stores for a small cost spoon


  1. Define sedimentary rocks to students. Have them make cracker/p. butter stacks to show the layers in sedimentary rocks.
  2. Introduce and define metamorphic rocks. Have students take/choose 3 pieces of taffy and 2 pieces of waxed paper. Unwrap the taffy and stack them up on 1 piece of waxed paper. Cover with the other waxed paper and press down. Discuss their "metamorphic rocks".
  3. Introduce and define igneous rocks. Have students spoon melted/molten candy into the molds. As it cools and hardens, it takes on the shape of the mold. Students can break the candy and look for any crystals of sugar.
  4. Finish the lesson by calling out the type of rock and having the students hold up the correct rock model they have make. Then eat the rock creations.