watercolor of kids holding crystals

How To Grow Crystals Overnight

This exploration is for all ages, as the colored smilies show. Growing crystals is fun for your whole family!

1st thru 4th grades
5th thru 8th grades
9th thru 12th grades

Rocks, a unit from the Earth & Space course.

The growing crystals earth science experiment comes from Earth & Space: Rocks. Layers of Learning has hands-on experiments in every unit of this family friendly curriculum. Learn more about Layers of Learning.

New rock is formed from cooling magma. When the magma cools underground it cools more slowly and forms crystals. The crystals formed depend on the mineral content of the magma and the cooling rate. If the magma cools very slowly, sometimes large crystals can form into gems.

In this experiment we’ll make crystals from borax. The borax crystals will have a definite shape and regularity, just like crystals formed under the surface of the earth.

Step 1: Library Research

Before you begin experimenting, read a book or two about gems and crystals. Here are some suggestions, but if you can’t find these, look for books at your library about gems. The colored smilies above each book tell you what age level they’re recommended for.

As Amazon affiliates, the recommended books and products below kick back a tiny percentage of your purchase to us. It doesn’t affect your cost and it helps us run our website. We thank you!

Rocks and Minerals

by National Geographic Kids

An easy reader for younger kids, or read aloud to pre-readers and beginners. This mostly talks about how rocks and minerals and gems form.

Rocks, Minerals, & Gems

by Miranda Smith

Full of gorgeous full color photos on every page of rocks, minerals, and gems, this book explains each type from its formation to how it is used today. Just let your kids browse through and pour over the images.

The Rock & Gem Book

by DK

Also, great for middle grades, this colorful book is packed with information in tidbits about gems and rocks and how they are formed.

Step 2: Growing Crystals Experiment

You will need wide mouth jars (about 36 oz or 1 L), food coloring, chenille stems (pipe cleaners), string, pencils (or a dowel or short stick), borax, and water.

Save a peanut butter or large jelly jar for this.

Start by forming your pipe cleaners in whatever shapes you’d like.  You can make snowflakes, swirls, letters of the alphabet – whatever you can form from a pipe cleaner.

Next, tie a string on to your pipe cleaner formation.  Tie the other end of your string on to the center of a pencil.  You want to make the length of the string adequate so the pipe cleaners will hang down into your jar, but not touch the bottom.

Fill a wide-mouth jar with boiling water.  Add Borax to the jar, 1 Tbsp. at a time.  Stir it in to dissolve it after each tablespoon.  You should add enough for a ratio of 3 Tbsp. of Borax for every cup of boiling water you put in the jar.  Add some food coloring if you want your crystals to be a specific color, and stir that in to the mixture as well.

Now suspend your pipe cleaner creation into the full jar, allowing it to hang freely from the pencil.  Let it sit overnight, undisturbed.

crystals forming in jars

By the next morning you should have some beautiful crystals!

crystals grown overnight

Step 3: Show What You Know

Look at the crystals you made through a magnifying glass. Draw what you see.

Look for the faces and edges of the individual crystals. Can you tell how many sides each crystal has? Are all of the crystals the same?

Looking at crystals through a magnifying glass

Write a description of how your crystals formed. How is this similar and different to the way crystals form from magma under the earth?

Put your drawing and your description in a binder behind a divider labeled “science”.

Additional Layers

Additional Layers are extra activities you can do or tangents you can take off on. You will find them in the sidebars of each Layers of Learning unit. They are optional, so just choose what interests you.


Idaho is called the gem state because its mountains are full of rare and valuable gems, including star garnets.

Michelle mining at Emerald Creek

Our family was able to go search for star garnets at Emerald Creek campground in Idaho. Is there a place near you where you can go see gems or minerals in person?

Additional Layer

Most crystals take thousands of years to grow. The giant crystals in Cave of the Crystals, Mexico, have been growing for about 500,000 years.

See the man near the bottom right of the photo? Those are some big crystals!

Learn more about this cave and how the crystals formed in it.

Writer’s Notebook

Lots of stories include crystals because they are so beautiful and they seem like the could be magical.

Draw a picture of a “magical” crystal. Decide what powers it has. Who would want to posses it? What would they do to get it?

Free Samples

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4 thoughts on “How To Grow Crystals Overnight”

  1. Worked Great!! Did this with my preschool class today and was able to witness crystals forming just after an hour and lots by the end of the school day!

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