Growing a Crystal Rainbow
Disclosure: This post may include affiliate links through the Amazon affiliate program or other affiliate partnerships. If you click on a link and buy something, I may receive a commission at no additional cost to you.
Way back when I was in college and planning my wedding—which was snowflake-themed—I was all about the snowflake decor. I envisioned a winter wonderland with sparkly snowflakes everywhere. What I didn’t have was the money to buy all of the decorations I wanted. So I had the idea to grow my own snowflakes. I picked up a box of Borax, a jar, and some pipe cleaners from Walmart and set about growing my first snowflakes. I didn’t make it very far—I’ll share with you later why—but I loved the process and the results, and I was excited to share with my own kids how it works.
Considering we’re in the middle of a very hot summer, growing snowflakes right now didn’t seem entirely appropriate. (Although my son did ask me just last night, “Mom, are you excited for snow?”) We’ll save the snowflakes for this winter. But with a little imagination, you can grow crystals on all sorts of pipe cleaner shapes! My personal favorite is a rainbow. Here’s how to do it.
Supplies:
- Heat safe glass container *
- Water
- Borax (approximately 3 tbsp per cup of water) **
- Pipe cleaners (rainbow colors plus white)
- String/thread/wire to suspend rainbow
- Pencil/popsicle stick
- Plastic wrap
* I’m not kidding when I say it needs to be heat-safe. The decorative jar I used in college was not. After I’d made my first couple of snowflakes, I poured the solution to make another one. When I lifted the jar to move it, the bottom of the jar stayed on the counter. The glass had broken along the entire bottom perimeter of the jar. I got doused in very hot water, and the floor of our apartment was covered in Borax. I don’t want that to happen to anyone else! A better choice would be a wide-mouth canning jar, or even a beaker like I used this time. It’s heat-safe AND has straight sides, which make for easy in and out of the shapes. This is the exact one I have—the Grosche 1000ml beaker
** Be careful using Borax. You don’t want to inhale or ingest it, and you should also avoid skin contact. I let my kids help out with every other part of this project, but I handle the Borax.
First form your rainbow out of pipe cleaners. To do this I cut my pipe cleaners in half. I didn’t try to stack the pipe cleaners to look like a traditional rainbow. The colors are all there, but they’re a little bunched up. Once you have your rainbow arches, wrap white pipe cleaners around both ends. Make sure that it fits inside your container without touching the sides. The opening of my beaker is a little over 3.5”, and my rainbow fit perfectly.
Tie one end of your thread/string—or wrap your wire—around one of the arches, and wrap the other end around a pencil or popsicle stick—whatever you’re using to help suspend the rainbow in the solution. (I thought I had centered mine a lot better until it was already in the solution. Oops.)
Next boil your water in a saucepan. You’ll need more than enough water to cover the rainbow. I filled my jar to the level I wanted and then dumped the water into the pan. Once the water reaches a boil, turn off the burner. It’s time to add the Borax. You can do this in the pan or pour the water into the container first.
Start mixing in the Borax a tablespoon at a time. Eventually you’ll reach the point where no more will dissolve, and that’s when you know you’re done. It’s okay if some Borax settles on the bottom of the jar.
Now you can suspend the rainbow in the solution, resting the stick/pencil across the top of the container. Make sure the rainbow doesn’t touch the bottom. I wrapped the thread around the popsicle stick a couple of times. Cover the container with a piece of plastic wrap. Make sure you put it somewhere that it can remain untouched overnight. You don’t want to even bump it while the crystals are forming.
Check on your rainbow the next day, and if it’s looking good, take it out! You can let it dry on a paper towel or blot it gently. We started at about noon and watched the crystals form all day, and then we still let them sit overnight. Looking at the time-stamp on my photos, it looks like we kept ours in the beaker for about 27 hours. You can certainly pull yours out sooner if you’re happy with it though.
If you’re not happy with your crystal growth, you can reheat the Borax solution and put the rainbow back in it. New crystals will grow over the old ones. I’m going to have to try this when I make snowflakes again.
If you want to preserve your crystals, you can use a clear acrylic spray to coat them. This is especially good if your rainbow will be handled a lot. I hung mine from our kitchen chandelier, and it’s so pretty to look at every day. I did not coat the last crystal rainbows I made, and the crystals turned white eventually. I’m hoping that by coating them this time they’ll stay clear.
For different variations on this project, you could of course make whatever shape you want out of the pipe cleaners. Snowflakes, stars, hearts—so many options! You can even wrap the pipe cleaners to form a nest of sorts, and you’ll end up with something that looks kind of like a geode. We used colorful pipe cleaners and let the colors show through the crystals, but if you want the actual crystals to be different colors, you can add food coloring to the solution. So many possibilities!
