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Borax Crystal Star/Snowflake – SICK Science!

Here’s an easy and amazing way to grow colorful borax crystal decorations overnight.

Bringing real snowflakes inside one-at-a-time is next to impossible. The snowy globs on your shoes and gloves don’t count, either.  So, to work around this conundrum, here’s a solution using the Borax Crystal Snowflake instead of real snow. This special snowflake is almost just as beautiful and unique as a snowflake you capture from the sky. However, it won’t melt and it’s a heck of a lot easier to see! Besides, the Borax Crystal Snowflake uses some fun, hands-on chemistry and makes a perfect holiday experiment for a perfect holiday decoration.

Experiment Materials

  • 3 Pipe cleaners (white, if possible)
  • String
  • 3 Wide-mouth containers (boiling-water safe)
  • Borax (laundry section of a grocery store)
  • 3 Pencils
  • Boiling water
  • Food coloring (optional)
  • Scissors
  • Adult supervision

Experiment Videos

Experiment

1

You may have three or more pipe cleaners because you want to make three or more Borax Crystal Snowflakes. That’s great! These directions tell you how to make one so duplicate them if you’re making more. With the scissors, cut a pipe cleaner into three equal sections.

2

Twist together the three sections of pipe cleaner at their centers to form a six-pointed star. Don’t stress if the sides aren’t perfectly even. Little imperfections make them more beautiful and natural.

3

Compare the size of your snowflake to the width of the opening on the container. The shape needs to fit easily into the container without any squeezing. It can’t even be close to allow for crystal growth. If it can’t easily fit, shorten each section as needed.

4

Cut a 10” (25 cm)  length of string.

5

Tie one end of the string to the center of the pipe cleaner snowflake. Lay the pencil across the opening of the container and lower the pipe cleaners into the container. The snowflake can be close to but should not touch the bottom of the container.

6

Tie the other end of the string to the pencil so the snowflake hangs freely in the container. When you have your string tied and set, lift the pencil and the snowflake out of the container and set it aside.

7

Make sure the container is safe for boiling water! Bring a pot of water to a boil and fill the container with it.

8

Add 3 tablespoons of borax powder for each cup (237 ml) of water in the container. Stir the solution carefully since it’s hot and try to get all the borax to dissolve. It’s OK if some borax settles to the bottom of the container.

9

If you want a colored snowflake, stir in some food coloring. More coloring is probably better than less. Lower the snowflake into the hot, colored solution and let it sit, undisturbed overnight. Moving or bumping the container while the crystals are growing is not a good idea so put it in an out-of-the-way place. The next day, carefully lift the pencil and check out the gorgeous crystals! Untie (or cut) the string from the pencil and you’ve got yourself a beautiful, sparkly holiday decoration!

How Does It Work

When you mixed the borax and water, you created a suspension of borax. A suspension is a mixture that contains solid particles large enough to settle out but almost too tiny to see. It looks murky. By mixing the borax into hot water, instead of room temperature or cold water, the borax stays suspended much longer within the water. Hot water holds more dissolved borax than cold water. Hot water molecules are moving very fast and are spread way out which makes space available for more borax to dissolve. As the solution cools, the water molecules slow down and move closer together. That means there’s less room for the dissolved borax.

As the borax molecules settle out out of the cooling suspension due to gravity, they bond with other borax molecules on nucleation sites (bumps, tiny cracks, impurities, etc. in the container) and begin to form seeds for further crystallization. You’ll see this crystallization on the bottom and sides of the container, on the string hanging from the pencil, and on the pipe cleaner arms of the snowflake. The borax continues to fall and crystalize on top of the snowflake and on top of other borax crystals until you pull it out of the water the next morning.