This Planet Really Rocks

Literature Activity

The Stone-Faced Boy

by Paula Fox

This is a book that everyone will enjoy reading.

In this book, Aunt Hattie gives Gus Oliver a geode, a rock with crystals inside. The creation of geodes occurred millions of years ago. Their existence started as a bubble of gas inside the volcanic layers of the earth's crust. Water inside these bubbles evaporated over time, leaving behind the minerals which eventually formed into crystals. Every geode is different; no two are alike. Opening a geode is like opening a treasure chest filled with beautiful crystals.

After reading this book, you will want to follow the directions below to create your own geode.

Eggshell Geodes


Materials needed:
  • hot plate
  • mineral salts
  • eggshell halves
  • tweezers
  • beaker tongs
  • large beaker (heatproof)
  • small beaker (heatproof)
  • goggles
  • water
  • egg carton

Procedure:

  1. Prepare your eggshells by using tweezers and removing the inside skin from the eggshell. (Do this very carefuly so as to not crack the shell.)

  2. Place a large beaker of water on the hot plate and heat the water until it is hot. (The water does not need to boil).
    REMEMBER TO WEAR YOUR GOGGLES!


  3. Using the beaker tongs, pour about 100 ml of hot water into a smaller beaker.

  4. Pour mineral salts into the hot water and stir until no more will dissolve. This will give you a saturated solution of mineral salts.

  5. Pour this saturated solution into the clean eggshell. Fill each eggshell about 3/4 full of the solution.

  6. Place the eggshell in an empty egg carton and place it where it will not be disturbed until the water has evaporated.

Follow Up:

  • Observe the eggshell each day and record what you see.
  • Explain how this geode resembles a real geode
  • Tell what part of the geode that the eggshell represents.
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