Break out the Borax for this colorful St. Patrick’s Day craft! Grow your own crystal rainbows overnight by applying simple principles of chemistry and suspension science.

 

You will need:
Heatproof glass jar, container, or measuring cup
Dowels, wooden spoons, or pencils
Kitchen string
9 tablespoons of Borax
Fuzzy pipe cleaners

DIY, Crystal, Rainbow

Boil 3 cups of water. While your water boils, place your pipe cleaners in spectrum order and shape then into a rainbow. Note: unless your heatproof container is deep and wide enough, you will probably have to trim your pipe cleaners down to almost half.

DIY, Crystal, Rainbow, SciencePipe cleaner, Crystal, Rainbow

To bind the rainbow together, use a white pipe cleaner as a “cloud” on either end.

DIY, Crystal, Rainbow, Science

Once your rainbows are shaped, tie a kitchen string or thread around the top pipe cleaner. This is how you will hang it over the Borax solution.

DIY, Crystal, RainbowDIY, Crystal, Rainbow

With some probable trial and error, tie your rainbow around your dowel and hang it from your heatproof jar. You want to make sure that the rainbow will not touch the sides of the jar or the other rainbow. This needs to be true when the liquid is poured into the jar, as your rainbows need to be submersed. This is where using a glass measure cup was helpful. The three-cup marking made it clear where to hang the rainbow.

DIY, Crystal, Rainbow

Remove your dry rainbow for the heatproof jar and have it at the ready. Scoop out 9 tablespoons of Borax into a separate, heatproof bowl and pour in the three cups of boiling water (it proved easier to stir in a big bowl, then transfer the solution to the measuring cup). Stir with a metal spoon until Borax is dissolved. The solution will be cloudy.

DIY, Crystal, Rainbow

DIY, Crystal, Rainbow

DIY, Crystal, Rainbow

With your rainbows attached to your dowels, lower them into the solution. Again, you want to make sure they are not touching the sides of the jar or each other.

DIY, Crystal, Rainbow

Let your rainbows hang overnight. It is important to NOT touch them or move the jar around. Your jar must remained in an indistrubed state. After a few hours, crystals will begin to form.

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And now the true reveal: the next morning. Loads of crystals!

DIY, Crystal, Rainbow

Pull out the rainbows slowly, and then give them a quick rinse.

DIY, Crystal, Rainbow

The results are amazing. The kids will be so impressed!

DIY, Crystal, Rainbow

DIY, Crystal, Rainbow

DIY, Crystal, Rainbow

The science behind it: When you mix the Borax with the boiling water, it may look like it completely dissolves. However, solid particles are still left over because you stirred up a saturated solution: a mixture where there’s more powder than the liquid can hold. As the solution cools down, these particles have to settle somewhere, and in this case, it’s on the fuzzy pipe cleaners provided. The important part is to leave it all undisturbed, allowing the particles to become bigger than the solution. This is known as suspension science.

 

Happy St. Patrick’s Day!

DIY, Crystal, Rainbow