How to Make Salt Crystals

Large Crystal

Making salt crystals can be a fun project to do with a scout troop or at home with your family. To create salt crystals, you need to place a medium such as a string in cooling saltwater. The saltwater will be supersaturated with salt so that as it cools, the dissolved salt will begin to crystallize back into solid form. Over time, salt stalagmites should form.

Things You'll Need

• Glass jar with wide mouth.
• String
• Pencil
• Scissors
• Small pan

Instructions

1. Boil some water in a small pan.

2. Pour the water into a glass jar so that it's half full.

3. Add 2 to 3 tablespoons of salt to the water and stir until the salt is dissolved.

4. Tie a length of string to the middle of the pencil so that when you place the pencil on top of the glass jar, the string will not touch the sides. Cut the string so that it does not touch the bottom of the jar.

5. Place the pencil on the mouth of the jar and leave it in a safe, viewable place for 10 to 20 days. Examine it daily to watch the crystals change shape.

Tips & Warnings

• Use sturdy but thin string.

• Add food coloring to the boiling water to make colorful crystals.

• Do not eat salt crystals.

• Adults should oversee this experiment. Exercise caution around boiling water.

References

• Exploratorium - The Science of Cooking: Make a Salt Sculpture