Grow Sparkling Borax Crystals

3.8 based on 144 ratings
Updated on Mar 28, 2014

Get your child excited about Earth science by showing him how to make borax crystals at home! Using just a few materials, your child can start his very own borax crystal collection. As the crystals form, he'll get to see the process of crystallization firsthand and will grow to better understand the formation and structure of crystalline rocks and minerals.

Note: Adult supervision is recommended during the steps involving boiling water. Also, be sure the Borax is not ingested.

What You Need:

  • Pipe cleaners
  • Scissors
  • Pencil
  • String
  • Mason jar
  • Water
  • Borax
  • Oven mitts

What You Do:

  1. Discuss with your child what shape he would like to create: A star, a heart, a spiral, a snowflake? Once he has decided, help him form his shape out of pipe cleaners, making sure it fits through the opening of the jar you're using.
  2. While your child makes his pipe cleaner shape, bring a pot of water to boil.
  3. Have your child knot one end of a length of string around the pipe cleaner shape and the other end around the pencil. Carefully lower the pipe cleaner shape into the jar, then lay the pencil across the rim of the jar. If the pipe cleaner touches the bottom of the jar, adjust the string so that the pipe cleaner hangs freely. Lift the pencil to remove the pipe cleaner shape from the jar, and then set it aside.
  4. Carefully pour boiling water into the jar, filling it until it's about three-quarters full.
  5. Have your child add borax to the water, one tablespoon at a time, stirring after adding each one is added. After 4 tablespoons have been added, check to see if the borax has begun to collect on the bottom of the jar. If not, have your child add more borax to the jar, one tablespoon at a time, until a small amount has collected on the bottom.
  6. Explain to your child that hot water can hold more borax than cold water. The crystals will grow on the pipe cleaner as the water cools and begins to release the borax.
  7. Have your child lower the pipe cleaner shape into the jar, laying the pencil on top as before. Make sure the pipe cleaner is fully submerged in the solution.
  8. Using oven mitts, carefully move the jar to a safe place where it won't be disturbed.
  9. Let the jar sit for 24 hours. Have your child periodically check the progress of his crystals to see how they are growing. Explain to your child that the borax molecules are attracted to each other even when they are in the water. First the molecules form small crystals and then larger ones as they attach themselves to the pipe cleaner. Once the pipe cleaner is covered in crystals, remove it from the solution.
  10. Hang your crystal in a window and enjoy its sparkling beauty!