Crystals are fascinating to kids and adults! We created these gorgeous, sparkling eggshell geodes for a homemade crystal growing science activity. We love this science craft with borax crystals, and there are a variety of ways to make them! Learn how to set up this eggshell geode science experiment. Simple science and STEM for kids everywhere.
MAKE EGGSHELL GEODES WITH BORAX
Cool chemistry for kids you can set up in the kitchen! If you have a rock hound like I do, then anything having to do with rocks and crystals is sure to please. Plus you can sneak in some awesome chemistry.
Growing eggshell geodes with borax is a simple way to introduce what a crystal is, the recrystallization process, making saturated solutions, as well as solubility! You can read more about the science behind our eggshell geode experiment at the bottom of this page!
WHAT IS CHEMISTRY FOR KIDS?
Let’s keep it basic for our younger or junior scientists! Chemistry is all about the way different materials are put together, and how they are made up including atoms and molecules. It’s also how these materials act under different conditions. Chemistry is often a base for physics so you will see an overlap!
What might you experiment with in chemistry? Classically we think of a mad scientist and lots of bubbling beakers! Yes there are reactions between bases and acids to enjoy, but also crystal growing! Chemistry involves matter, changes, solutions, and the list goes on and on.
We will be exploring simple chemistry you can do at home or in the classroom that isn’t too crazy but is still lots of fun for kids! You can check out some more chemistry activities here.
HOW TO MAKE EGGSHELL GEODES
Luckily you don’t need expensive or special supplies. In fact you can make eggshell geodes without allum and make them instead with borax powder!
You can also use that borax powder for awesome slime science too! Check the laundry detergent aisle of your supermarket or big box store to pick up a box of borax powder.
ALSO CHECK OUT:
EGGSHELL GEODES SUPPLIES LIST
- 5 Eggs
- 1 ¾ cup Borax Powder
- 5 Plastic Cups (mason jars work well too)
- Food Coloring
- 4 Cups Boiling Water
EGGSHELL GEODES CRYSTAL PROCESS
First you want to carefully crack each egg so you can reserve lengthwise halves. If you are lucky, you may be able to get 2 halves from each egg.
You need at least 5 halves to make a rainbow assortment of crystal geodes. The egg inside can be discarded or cooked and eaten as you only need the shell. Cooking eggs is a great example of irreversible change!
Next, you can rinse each shell well and carefully pat them dry.
Bring 4 cups of water to a boil and stir in the borax powder until it is dissolved. There should be a little bit of borax on the bottom of the pan or container that does not dissolve.
This lets you know you have added enough borax to the water and that it cannot be absorbed anymore. (This is called a supersaturated solution).
You will want to set up your 5 cups in a location where they won’t be disturbed. Pour ¾ cup of the mixture into each cup. Next, you can add food coloring and stir.
NOTE: The slow cooling of the liquid is a huge part of the process, generally we have found that glass works better over plastic, but we had good results this time with plastic cups.
If your solution cools too quickly, impurities will not have a chance to fall out of the mixture and crystals may look disorganized and irregular. Generally crystals are quite uniform in shape.
Put an eggshell down into each cup making sure the inside of the shell is face up. You want the eggshells to get into the cups while the water is still very hot. Work quickly.
GROWING CRYSTAL GEODES IN EGGSHELLS
Let the shells sit in the cups overnight or even for two nights for plenty of crystals to grow on them! You don’t want to agitate the cups by moving them or stirring them, but make sure to check on them with your eyes to observe the process.
When you see some good crystal growth, remove the shells from the cups and let dry on paper towels overnight. Although the crystals are quite strong, handle your eggshells geodes carefully.
Encourage your kids to get out magnifying glasses and check out the shape of the crystals.
EGGSHELL GEODE EXPERIMENT RESULTS AND SCIENCE FACTS
Crystal growing is a neat chemistry project that is a quick set up involving liquids, solids, and soluble solutions.
You are making a saturated solution with more powder than the liquid can hold. The hotter the liquid, the more saturated the solution can become. This is because the molecules in the water move farther apart allowing more of the powder to be dissolved.
As the solution cools down there is all of a sudden going to be more particles in the water as the molecules move back together. Some of these particles will start to fall out of the suspended state they were once in.
The particles will start to settle on the eggshells and form crystals. This is called recrystallization. Once a tiny seed crystal is started, more of the falling material bonds with it to form bigger crystals.
Crystals are a solid with flat sides and symmetrical shape and will always be that way (unless impurities get in the way). They are made up of molecules and have a perfectly arranged and repeating pattern. Some might be bigger or smaller though.
Look how gorgeous science can be! Kids can easily grow crystals overnight.
MAKING EGGSHELL GEODES IS PERFECT CHEMISTRY FOR KIDS!
Want more great science? Download these simple ideas below. Join our community and get our FREE printable STEM calendar each month.