Make unique crystal snowflakes to hang in your window this winter.
This is what you’ll need:
- Pipe cleaner
- Pencil or skewer
- Ribbon (optional)
- Large Mason or other wide- mouth, heat-safe glass jar
- 1-cup measuring cup
- 9 Tbsp. Borax (look for this in the laundry soap section of the store)
(Note: You can make salt or sugar crystals instead of Borax)
- Hot water
- Food coloring (optional)
- Adult guidance is recommended especially for pouring boiling water and handling Borax.
- If you prefer to make sugar or salt crystals, they will take a couple of days to grow and the crystals are smaller. The salt and sugar crystals are edible, but DO NOT EAT Borax.
- To make the snowflake shape, cut a white pipe cleaner into three equal sections.
- Twist all three sections together in the center so you end up with a six-sided shape. Spread out the six arms to form a snowflake skeleton.
- Cut a piece of string about six inches long. Tie one end of the string to the top of one arm of the snowflake.
- Lower the snowflake into your jar holding the end of the string. Make sure the snowflake can be pulled in and out of the top of the jar without touching any part of the jar – sides or bottom. If the snowflake arms touch the jar, trim them with scissors.
- With the snowflake in the jar, set the pencil across the top of the jar, and roll the end of the string around the pencil until the snowflake floats in the jar without touching the bottom or sides of the jar. Tie the end of the string around the pencil to hold the string at this length.
- Remove the snowflake-string-pencil assembly, and put it aside.
- With an adult’s help, boil about 3 cups of water using a teakettle or heat-safe container in the microwave. Remember to make sure your snowflake jar is heat-safe too!
- Ask your adult to pour the boiling water into your jar. Your jar should be about ¾ full. A large Mason jar will hold 3 cups of water nicely.
- Now add 3 Tablespoons of Borax to the jar for each cup of water added. Stir until all of the Borax dissolves. If you used 3 cups of water, add 9 Tbsp. of Borax.
- Lower your snowflake into the jar and rest the pencil across the open jar top. Make sure the snowflake isn’t touching the jar and all of the pipe cleaner is covered by the solution. Set your jar somewhere safe where it won’t be disturbed. The waiting begins! Formation of your crystal creations can take up to several days.
- The next day, or the day after, carefully remove your snowflake from the jar and set it on a paper towel to drip dry.
- Cut the string off the pencil or cut it off the snowflake and replace it with ribbon.
- Your crystal creation is ready to hang in a window or on a tree!
- When you’re done playing with your snowflake, make sure you wash your hands.
Take it further:
- Measure the size of some of your crystals. How long is your biggest crystal? How many different sizes are there? Do you grow more crystals or bigger crystals if you let the snowflake sit in the solution longer?
- Try it again, but use sugar or salt instead of Borax. It will take longer to grow these crystals (up to a few days), so be patient! Do the crystals look the same? Which do you like best?
- What does your snowflake look like when light hits it? Does it reflect light? Does light go through it? Does it look different in sunlight versus light bulb light?
- Make a more intricate snowflake by wrapping string around and between the simple snowflake’s arms to create a more detailed frame before it goes in the solution. Do crystals grow on the string too? Are they the same size as the crystals on the pipe cleaner?
- Create colored snowflakes with colored pipe cleaners and/or a few drops of food coloring in your solution before you add your snowflake skeleton to the jar.
What’s going on?
We used boiling water for this experiment so we could dissolve more Borax in the water than if we’d used cooler water. The hot water molecules move around more quickly and are farther apart from each other than cold or even room temperature water molecules, leaving more space for Borax molecules to dissolve into the water – more of them “fit” in the water because of the extra space between the hot water molecules. The hot solution with a lot of Borax dissolved in it is called a supersaturated solution! As the solution cools, the Borax begins to crystalize on the pipe cleaner because the water can’t hold that much Borax anymore. At room temperature, it holds less Borax; this is called a saturated solution.
Crystals started forming when the solution was supersaturated. The pipe cleaner and string give the molecules something to hold onto. The molecules then stack onto each other like blocks. More Borax molecules attach to these small starter crystal “seeds,” which keeps the crystals “growing” until most of the Borax has crystalized. This keeps happening and it looks like the crystals are growing, but they aren’t alive. The crystals will “grow” until there isn’t any Borax left or until you take your snowflake out of the solution.
Were your crystals big or small? The more time the solution has to cool, the bigger the crystals will get until they reach their maximum size. If we cool the solution quickly, say by putting the jar of hot water in a bucket of ice, the crystals will be smaller because the Borax molecules don’t have much time to organize themselves and join together to make big crystals.