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Grow a Crystal Rainbow with Kids

Grow a Crystal Rainbow with Kids

Growing your own crystals is so much fun and a fun Science experiment any time of year, but growing your own rainbow crystals seems perfect for St. Patrick’s Day!

Kids of all ages will enjoy this fun experiment and watching the chemical reaction happen in this crystal science experiment. Here’s how you can grow crystal rainbows in a few easy steps with a few simple ingredients that you can find at the grocery store. 


Crystal Rainbow Supplies


  • 4 cups water
  • ½ cup Borax detergent booster
  • 6 pipe cleaners (colors of the rainbow)
  • scissors
  • mason jars or glass jars
  • string
  • craft stick or clothes pin



Make a rainbow from 6 pipe cleaners by twisting the ends of the pipe cleaners on both sides and bending them into a rainbow shape.



Tie a piece of string around one end of the bundle of pipe cleaners. Scoop 1/2 cup Borax powder into a glass jar. 


Boil 4 cups of hot water and pour it into the jar (an adult should pour the boiling water). Pour it slowly to allow the temperature to adjust so the jar does not crack. Stir until the Borax is dissolved. 



Attach the string to a popsicle stick or clothes pin by tying a knot. Carefully drop the pipe cleaners into the borax solution below the surface of the water so that the they hang in the middle of the jar without touching the sides of the jar or the bottom of the jar. 


Grow a Crystal Rainbow


Salt crystals will begin forming as the mixture cools. Beautiful crystals will form on the pipe cleaners in as little as two hours.

Have fun watching the crystals form, but wait until the next day to take the crystal formation out of the jar.


Crystal Rainbow Science Experiment

Take the pipe cleaners out of the jar and allow them to dry completely. 

Use the thread to hang the chenille stems. They make beautiful sun catchers. Or cut the string off and set the rainbow on a plate.


More Crystal Experiments

  1. Make different shapes with the pipe cleaners (stars, a cross, or candy canes). You can even turn them into crystal Christmas ornaments.
  2. Keep experimenting. What will happen if you use white pipe cleaners and food coloring? 
  3. How long can you leave the crystals in the jar until they stop growing? What can you do to create bigger crystals?


More Simple Science Experiments

Try these simple Science fair Science experiments with your kids (even if they aren’t for the Science fair).

Some of the experiments include:

  • walking on eggs
  • liquids and magnets
  • fingerprints
  • sunscreen and the sun
  • make a solar oven




Make your own anemometer and experiment with the wind. This is a fun experiment that uses simple items you probably already have at home. 


More Rainbow Science Experiments

Ready for more St. Patrick’s Day Science? Check out more fun ways to create and experiment with rainbows!


Make and experiment with a DIY rainbow scope. This is a fun St. Patrick’s Day craft and it is a great way to create a rainbow anywhere!



Walking Water Experiment from Life over Cs. The best part of this science project is seeing the water absorb in the paper towels and travel. Such great rainbow fun!


Friday 5th of March 2021

This looks so fun! Can’t wait to try this with my kiddos! Thank you for sharing.