STEAM Connections: Crystal Creations

Ever wanted to see how gemstones and other crystals are formed? Grow your very own crystal using basic household supplies.

Crystals form when molecules are connected in regular, repeating patterns. Their geometric shapes often feature sharp, straight edges and facets, or smooth sides. Crystals take the shape of the molecules that form them, locking together in an orderly fashion.

The process of crystals forming is called crystallization. Crystallization occurs in nature when liquid cools and starts to harden, like magma cooling into a mineral quartz crystal, or when water evaporates from a mixture – this is where sea salt comes from.

Check it out and follow along with our video below:

STEAM Connections

In this experiment, watch borax crystals form in just a few hours as a cooling mixture causes borax molecules to fall out of the liquid and recrystallize.

Supplies

Below is what you will need to conduct this STEAM Connections experiment:

1 cup boiling water
1/4 cup borax
5 – 8 pipe cleaners
Large heat-safe glass container
Scissors, to cut pipe cleaners

Instructions

Make predictions in your scientific notebook, including a sketch of what you think your crystal will look like.
Bend pipe cleaners into the shape you want your crystals to grow.
Prepare borax solution by bringing water to a boil and dissolving Borax in the water. Keep adding borax until it stops dissolving in the water (this is when solubility is occurring). You can add food coloring to the mixture if you want the crystals to have some color. Set the mixture aside to cool.
Pour mixture into a container that is slightly larger than the pipe cleaner structure.
Leave in a safe place, such as next to a sunny window, to allow crystals to form.
Check after a couple of hours and dislodge your structure from its container.

Review

As you experiment, record your observations:

What do you notice about the shape of the crystals?
Did the crystals grow on the pipe cleaner?
How did the shape of the pipe cleaner affect the crystal shape?
Does placing the mixture on a sunny windowsill make a difference from storing it in a cold cupboard?
What happens when you repeat the experiment using salt or sugar?

Crystallization occurs in the mixture because the heated water has greater solubility, which is the ability of the borax to dissolve in the water. When the mixture becomes saturated, the maximum amount of borax has dissolved into the water. As the water cools, solubility decreases, causing borax molecules to fall out and form into solid crystals.

Conduct additional experimentation and try to grow salt, sugar, or Epsom salt crystals. What do the new crystal structures look like? How do they differ from the borax and each other?

Continue Learning

Here are some items and books in the library collection you can check out to learn more! You will need a Plano Public Library card to access these materials.