Itching to break out the Easter eggs early this year?  Here’s a fun family experiment to really beautify those eggs, although you might not want to use them for an Easter egg hunt once they look this pretty.



  • Alum powder (must have potassium in it to get the crystals to grow)
  • Eggshells (plastic or real, either will work)
  • Elmer’s glue
  • Cheap paint brush
  • Shoe box (or some other safe place for your geodes to dry)
  • 4 cup bowl
  • Spoon or whisk
  • 3/4 cup measuring cup



  • Use your paint brush to apply a thin layer of glue to the inside of your egg, everywhere you want your geodes to grow.  This glue will need to dry completely before you begin the process.   Do not allow the glue to puddle int he bottom of the egg shell.
  • While the glue is still wet sprinkle the egg with the alum powder.  Of course you could always just fill the egg with the powder and then dump the rest of the powder back into the measuring cup making sure to get a good coating of alum powder on your egg shells.
  • Now it’s time to let the glue dry, ideally this can happen over night, but if you were successful at applying only a thin layer of glue perhaps this will take just a few hours.  Regardless make sure the glue is really dry before proceeding to the next step.
  • Add 2 cups of water to your 4 cup bowl and heat the water to almost boiling (5 minutes in the microwave will do, if it boils during this time that’s okay too, since the boiling will stop as soon as the microwave door opens.
  • Add 3/4 cup of alum powder and stir/whisk until the powder dissolves.  Feel free to put the mixture back in the microwave for a minute or two if you feel you need more heat.  You may also add dye to your mixture during this time as well.  Food coloring or Easter egg dye will work.
  • Once you’re satisfied that the mixture is sufficiently saturated, drop an eggshell or two into the mixture.  You’ll want to leave your shells there until tomorrow, after about 24 hour examine your egg shells and see if you are happy with the size of the geodes, if you want the crystals to grow bigger drop them back in the solution and wait another day or two and they will continue to grow.
  • You can continue this process until all of your eggs are coated, once you’re done, pour it down the drain and wash your bowl.  Alum is an edible pickling spice so it’s safe for disposal in the sink.