Grow Eggshell Geodes Crystal

Crystals exert such fascination on kids. Our Grow Eggshell Geodes Crystal teaches you how to turn your eggs into beautiful alum-crystal geodes. It is the best idea to try at Easter at home with your kids.

Age: 5+          Time: < 4 hours

 Safety 

1. Adult supervision.
2. Borax is toxic. Do not eat it.

 Materials List 

• Borax
• water
• Heater
• Eggshell
• Painting brush
• Glue
• Food coloring (optional)
• Beaker
• Pot

 Instruction 

Step 1/6 – Boil about 500ml water into the pot.

Step 2/6 – Add the borax to the boiling water until the borax can not be dissolved in the water anymore.

Step 3/6 – Pour the borax solution into a beaker and add 2~3 drops of food coloring.

Step 4/6 – Glue the inside of the eggshell and Use a painting brush to spread the glue all over the inside of the shell.

Step 5/6 – Put the eggshell in the borax solution and wait for about 3 hours.

Step 6/6 – Take out the eggshell and you have your eggshell geodes crystal.

 Troubleshooting 

Why my eggshell did not grow the crystal?
— You can leave the eggshell in the borax solution for a longer time, You also can coat the inside of the eggshell before putting it into the borax solution. Make sure you add the borax to the boiling water until the borax can not be dissolved in the water any longer.

 Scientific Description 

The principle behind this experiment is Supersaturation which is a solution that contains more of the dissolved material than what could be dissolved by the solvent under normal circumstances. Supersaturation is an unstable state. When the pressure is constant, the solubility of borax at high temperatures is higher than that at low temperatures. So when the temperature goes down the borax solution is supersaturated. The extra borax molecules begin to settle down to the shell as well as on the bottom and sides of the bowl. The glue on painted on the eggshell is to attract the borax molecules.

 Extensions 

1. You can add different food coloring to grow different colored eggshell crystals.
2. You can grow the crystal on the pipe cleaners.

 Disposal 

Borax is harmful to the environment, It is best to evaporate the left solution to have the borax crystal and keep the solid for the next use.