Place water in the mason jar and microwave for 2-3 minutes or until the water just starts to boil.
Using oven mitts, carefully remove the jar from the microwave and add the borax.
Stir until the borax is completely dissolved.
Form the pipe cleaner into a peppermint candy cane shape small enough to fit easily within the opening of the mason jar without having to bend it.
Tie the string to the top of the peppermint candy cane shape, then tie the other end of the string to the center of the wood skewer with enough length to allow the candy cane to be fully submerged in the borax and water mixture without touching the bottom of the jar.
Once the string is tied firmly, slip the peppermint candy cane shape into the jar and use the skewer to hold the candy cane suspended in the liquid by resting the skewer across the opening of the jar.
Place the jar in a location that it will not be disturbed and allow it to rest for 24 hours.
Gently lift the skewer to remove the peppermint candy cane crystal and discard the borax mixture.
Place the crystal candy cane on a clean, dry surface to dry and trim off the string. Then display.