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Activity: Crayon Rock Cycle
NGSS Science and Engineering Practices
NGSS Crosscutting Concepts
NGSS Disciplinary Core Ideas
Table of Contents


  • Crayons of different colors
  • Crayon sharpener
  • 2 pieces of wood or heavy books
  • Candle or hotplate
  • Safety goggles
  • Ruler
  • Heavy duty aluminum foil
  • Tongs
  • Water
  • Cup (for water)
  • Matches


Safety note: Use caution when using matches or open flame. Be sure that you are in an area free of flammable items, and never leave fire unattended.

  1. Define metamorphic, sedimentary, and igneous rock in your own words.
  2. Fold a piece of aluminum foil so that you have a 10 cm by 10 cm square of double thickness. Repeat this process so you have two pieces of folded foil.
  3. Use the crayon sharpener to make crayon shavings of several colors.
  4. Sprinkle crayon shavings in the center of one of the double-thick aluminum foil pieces. Place the second piece of aluminum foil on top of the shavings. Fold the edges together to create a packet so that the crayon shavings do not fall out.
  5. Place the aluminum foil packet in between two pieces of wood or heavy books and lightly push down on the books to flatten the shavings.
  6. Predict what the shavings will look like when the foil is opened. Record your prediction.
  7. Open the foil packet and observe the shavings. Record your observations.
  8. Rewrap your packet. Place the packet between the books. Apply more pressure by adding more books or other heavy objects and pushing down hard on the packet. Predict what the crayon shavings will look like when unwrapped. Record your prediction.
  9. Open the foil packet and observe your crayon shavings. Record your observations.
  10. Put on your laboratory safety goggles.
  11. Rewrap your foil packet. Light the candle or other heat source and hold the packet over the flame with tongs for several minutes.
  12. Remove your packet from the flame. While the packet is cooling make a prediction about what the crayon shavings will look like when the foil is removed. Record your predictions.
  13. Ensure that the foil packet is fully cooled by submerging it cold water. Remove the foil covering and observe the crayon shavings. Record your observations.


Activity Questions
  1. Did your predictions match your observations for each of the procedures? Explain why you think your predictions closely matched, or were different than, your observations.
  2. Discuss your model of the rock cycle.
    1. What do the crayon shavings represent?
    2. What did each of the stages represent?
    3. What did each type of crayon formation represent?
  3. If you did this activity again, what would you do differently to better approximate the rock cycle?
Exploring Our Fluid Earth, a product of the Curriculum Research & Development Group (CRDG), College of Education. University of Hawaii, 2011. This document may be freely reproduced and distributed for non-profit educational purposes.