smooth beach rocks
borax (in the UK, you can order Borax online here)
hot water
jars or plastic containers
spoon
liquid watercolours
medicine droppers or small paintbrushes
First we filled a jar with 3 cups of very hot tap water. Then we added 9 tablespoons of borax. We stirred and stirred until the borax had dissolved. Then, using a spoon, we lowered our rock into the jar of borax-water, and left it on the counter to do its thing.
Crystals began to form on the rock and on the bottom of the jar within hours. To maximize the crystallization process, we left our rock in the borax solution overnight.
The next day, the crystals had kind of cemented the rock to the bottom of the jar, so we used a spoon to gently pry it loose. Take care to not force the rock free too quickly. You could chip some of the crystals off your stone.
We placed our stone on a paper towel to dry.
If you’re crystallizing a bunch of rocks like I did, pour your borax and water solution into several small containers or jars, and place one rock in each. I used small Gladware containers for the batch of rocks, making sure that each rock was completely submerged in the borax solution.
Now, to colour our crystals!
This part of the experiment was quick and easy, but WOW, was it ever impressive!
I poured a few drops of our liquid watercolours into an ice cube tray, and I added a couple of drops of water to each colour to dilute them a wee bit.
Then the hooligans used the droppers and paintbrushes to drip or brush the colour onto their rocks.
You should’ve heard the ooh’s and ahhh’s as the borax crystals soaked up the colour!
Most of the kids chose to colour their rock in one solid colour, dripping the colour on with the medicine droppers.
And now, it’s time for YOU to make some crystallized beach rocks of your own!