Little Scientists: Egg Geodes

Geodes are small rock cavities lined with crystals or minerals. They form through a process in which particles (solute) are suspended in fluid (solvent) and then accumulate. Have some fun creating your own Geodes with some basic house supplies! How many days does it take your crystals to grow?


  • Eggs
  • Epson salt
  • Glue
  • Egg dye (optional)


1. Wash and dry some eggshells. The bigger the shell pieces the better.

2. Dye shells. You can dye just the outside or the inside and outside to create different looks. (optional) Place the shells inside an empty egg carton or small bowl.

3. Coat the inside of the shells with a thin layer of glue and sprinkle with Epsom salt and let completely dry.

4. Boil 1 cup water. Once the water has been brought to a boil, remove it from the heat. Stir in 1⁄2 cup of Epsom salt and mix until it’s dissolved. Keep stirring in more Epsom salt a little at a time until the salt no longer dissolves. You can also add food coloring to your solution.

5. Slowly pour the solution into your shells.

6. Check your eggs daily. If a pocket of water develops, carefully break the surface with a pin or toothpick. ​In a few days, all the water will evaporate and crystals will become

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