How to Make Crystals With Table Salt

Grow salt crystals on a string in a jar at home.

Salt is a mineral called halite, made of cubic crystals, according to the Think Quest website. These crystals have square sides like a box. Minerals create crystals because the atoms---miniature particles---replicate in three-dimensions. This growth process results in the flat planes of the salt crystals. As an experiment, make your own salt crystals to watch how they develop. Use common household items to conduct a salt crystal experiment at home or in a classroom. It takes only a few days and common salt to produce your own crystals.

Things You'll Need

• Clear water glass or bottle---at least 2 inches wide across the top
• Stir sticks or other sticks, such as frozen treat sticks
• Regular string or thread
• Scissors
• Warm tap water
• Regular table salt
• Magnifying glass

Instructions

1. Add warm water from the tap to the clear container to make it half-full.

2. Use a stir stick to dissolve salt in the water. Keep adding salt until as long as the salt keeps dissolving.

3. Tie string or thread to the middle of a stick. Set the stick across the glass with the string hanging outside of the glass. Cut the string so it hangs free and won't touch the bottom of the glass.

4. Put the string in the water with the stick resting across the opening of the glass.

5. Check the salt crystals daily. The evaporating water leaves crystals forming on the string.

6. 

   Salt crystals form as the saltwater evaporates.

   Examine the salt crystals with a magnifying glass to see the shapes of the developing crystals.

Tips & Warnings

• As a learning activity, discuss cubes, prisms, and other kinds of minerals and crystals.

References

• Libary: Think Quest: Growing Crystals Activity

Resources

• Exploratorium: Science Explorer: Epsom Salt Crystals