Wednesday, August 4, 2010

Growing Crystals.

Last week my boy took a Science and Chemistry summer enrichment class offered by the schools. They did all kinds of neat experiments, made slime, polymer bouncy balls and grew borax crystals. The teacher provided a printout with directions for each experiment. He had so much fun with it we decided to do some of the experiments at home.

i was really impressed with the borax crystals and wanted to try this one. The instructions are simple. You need boiling water, borax, a wide mouth pint jar, a pencil, a piece of string and a pipe cleaner. You can also add food coloring if you like.

The first thing you need to do is boil your water. We used about two cups of water per pint jar. While the water is boiling, you can make a shape out of your pipe cleaner. It needs to be able to fit in the jar without touching the sides or bottom.

Tie the string to the pipe cleaner, and tie the other end of the string to the pencil. The pencil sits on top of the jar and holds the pipe cleaner suspended above the bottom of the jar. Once you have your pipe cleaner shapes the correct size/length, set them aside.

Add two cups of boiling water to the jar. Then add borax, one tablespoon at a time. Stirring well each time. You will add 3 TBSPs per cup of water. So we added 6 tablespoons of borax. It's okay if some undissolved borax settles to the bottom of the jar.

If you want to add food coloring, you can add a couple drops now.

Hang the pipe cleaner shape into the jar so that the pencil rests on top of the jar and the shape is completely covered with liquid and hangs freely (not touching the bottom of the jar). Within minutes, we could see the borax beginning to collect on the pipe cleaners.

After just a few hours, we could see actual crystals forming.

Let the jars sit in an undisturbed location overnight. We set ours on the window sill. In 24 hours the pipe cleaner shapes were completely covered in beautiful borax crystals. We removed them from the liquid and allowed them to dry a few minutes.

The crystals are pretty durable, and make a nice sun catcher. This is a really fun and easy project.

*taken from

The Science Behind the Fun

Borax is an example of crystal - "a solid with flat sides and a symmetrical shape because its molecules are arranged in a unique, repeating pattern."

Every crystal has a repeating pattern based on it's unique shape. They may be big or little, but they all have the same "shape". Salt, sugar, and Epsom salts are all examples of crystals. Salt crystals are always cube-shaped while snow crystals form a six-sided structure.

How do the Borax crystals grow?

Hot water holds more borax crystals than cold water. That's because heated water molecules move farther apart, making room for more of the borax crystals to dissolve. When no more of the solution can be dissolved, you have reached saturation. As this solution cools, the water molecules move closer together again. Now there's less room for the solution to hold onto as much of the dissolved borax. Crystals begin to form and build on one another as the water lets go of the excess and evaporates.

This also applies to snowflakes - As water cools the molecules move closer together. Since all water molecules are shaped the same (H2O) they align in a six sided crystal.


  1. Thanks!!! We're homeschooling this year and this will be great for the kids!

  2. awesome! I used to do this as snowflakes with my grade 4 science class. Love the different shapes and the colouring. I'll have to do it again with my own kids.
    thanks for sharing and commenting on my blog.

  3. I Love these! I've tried this before, but you have inspired me to do this again! I probably have the materials too. Love you blog!

  4. I love this I will have to dot his with my son this week.

  5. Neat! I was just blog hopping & came across your blog & clicked on this because it looks so fun & pretty. I wrote down the directions. My art-crazy 6 yr old will love it.

  6. This is awesome and I will try it with my Grandchildren !!!! Thanks for the great idea !!!

  7. I think I'm going to try this with my girl scout troop for mother's day gifts!
    Thanks for the great idea!