Learn to Make Geode Crystals at Home!

Welcome explorers! 

If you are wondering what these colourful crystals are, they are geodes. These are spherical-shaped rocks that form within sedimentary and volcanic rocks. They are mostly round with different sizes varying from a tennis ball to a softball. 

Though they appear as heavy rocks, they are hollow from the inside. The inner part of these rocks is lined with masses of mineral matters that are mostly crystals. If you break open these ordinary-looking rocks, you will be amazed to find shimmery-coloured crystals. 

Amethyst Geode in Crystal Mountain Museum. (Image source: Google)

How are they formed?

The name Geodes is derived from the Greek word Geodes, which means “earth-like.” They are created in the hollow areas of soil, like tree roots and animal burrows. Sometimes, they form in the volcanic rocks. They naturally pick up various minerals, including quartz, amethyst, and calcite. Gradually, they harden into an outer shell creating the geodes.

Where do you find them?

Geodes are mostly found in volcanic ash beds, areas with plenty of limestones, and deserts. Just like how every fingerprint is different, every geode is unique in its shape, size, and colour. 

What if we tell you that you can make these colourful crystals within a few days? 

Now, let’s learn how to make geode crystals using just four materials.

Steps for DIY Geode

You can make the geode shell in two ways: 

1. Crack open an egg at the narrow end. Rinse it in hot water to clean it from inside. 
2. In case you don’t find an eggshell, you can also use the Plaster of Paris to make the geode shell. Mix Plaster of Paris with water to make a thick solution. Take a coffee cup and press the solution against the sides and bottom of the cup to get a bowl shape. Allow the Plaster of Paris to set for 30-40 minutes and then gently remove the mold from the cup. 

The eggshell/the Plaster of Paris mold will be the geode shell for your crystals.

1. Pour a cup of hot water into a bowl. (Make sure to take help from an adult)
2. Slowly add alum and stir the water. (Add as much alum as you can until it stops dissolving and you see its particles sinking towards the bottom of the cup).
3. Add a few drops of food colour if you want a coloured crystal and stir gently. The food colour will not colour the crystal but will add a shade to the eggshell or the Plaster of Paris.
4. Take a large container (larger than the eggshell or the plaster mold) and place your geode shell in it. 
5. Slowly pour the alum solution into the geode shell until it is filled to the brim. Avoid pouring any undissolved alum.
6. Keep the geode with the alum solution in a safe place. Wait for a couple of days for the crystal to grow.
7. After a few days, all the water will evaporate leaving behind a beautiful coloured crystal.
8. Keep your geode shiny by protecting it from dust and humidity. You can also wrap it with a tissue paper or keep it in your showcase. 

Crystals are not only used for ornamental purposes. Look around you and you can find crystals everywhere – from snow to sugar and salt. Isn’t that amazing?

The world is full of surprising elements that come in tiny little shapes and sizes. All you need to do is keep exploring and keep learning! 

Will you make these colourful geode crystals? Do let us know in the comments below.

Liked this DIY activity? Learn more about other fun DIY activities:

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