How to grow geodes in eggshells

31 October 2025

Did you know you can grow crystals in an eggshell? Learn how to make your own egg geode in 3 easy steps.

Eggshell with a cavity filled with purple crystals.

Imagine a rock. Any rock. Not much to look at, is it?


Now imagine cracking it open and finding a treasure trove of crystals.


This isn't a fairy story. It's a real-life rock you can find in nature. And those crystals are old – thousands of years old, in fact.


This type of rock is called a geode – and it's proof that you should never judge a book by its cover. A geode may look as plain as a potato, but it's actually a natural treasure chest!


Geodes are formed when water seeps into rocks and hardens into crystals. But did you know that you can also grow your own geode in an eggshell? Here's how.


1. Gather your materials

First, you'll be working with hot water, which can cause burns, and epsom salt, which can be dangerous if swallowed. Make sure there's an adult around to supervise things before you start.


To grow your own geode, you need four things:

  • A raw egg
  • Epsom salt
  • Water
  • Glue


If you want your geode to be colourful (the shell, the crystals or both), you could also use some food colouring. You should also put down some newspaper or a plastic sheet to avoid staining the table.



2. Get your eggs ready

First, make a large hole in the eggshell and pour away the yolk and white. Try to keep the shell as intact as possible. You want to be able to pour liquid inside, but still have a nice enclosure for your crystals.

An eggshell broken on the ground. Brown dirt and a dark blue sky in the background.

Before you add anything to the shell, you need to wash and dry it.


If you want a colourful geode, you can now dye your shell with food colouring. You could do this to the inside, outside or both.


Once that's done, place your eggshell in an egg carton or bowl. Coat the inside of the shell with glue and sprinkle the glue with Epsom salt.


Now it's time to boil the kettle. Carefully pour the hot water into a heatproof jug and stir in more Epsom salt. Keep adding the salt until it stops dissolving. If you want your crystals to pop with colour, you can add food colouring to the mixture.


This is your geode juice. Let it cool and then pour it into a container with the egg.

A clear glass filled with a milky liquid rests on an orange surface against a dark blue background.

3. Watch and wait

It can take up to a few days for your crystals to grow. It takes time for the water to evaporate and the Epsom salt crystals to appear.

 
Watching and waiting is all part of the fun. What do you notice as the salt turns into crystals before your eyes?


As the crystallisation takes place, keep an eye out for any pockets of water. If you see one, break it with a pin.


And there you have it: your very own geode in an eggshell!

A cracked egg filled with sparkling blue crystals. The setting is a brown landscape against a dark blue background.

Geode cracking at Stump Cross Caverns

Would you like to see a real-life geode cracked open in front of your eyes? A geode you can take home and keep? Then Geode James's Geode Shack is the place to be.
When we crack your geode, you'll be the first person  ever to see the magic inside. Isn't that amazing?


It's easy to book a spot. Head to our online ticket portal and book for
geode cracking at Stump Cross Caverns today.

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