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How to Make Crystals With Iodised Table Salt

A salt crystal garden is a simple and fun science project for any home or classroom. Sodium chloride is a crystalline compound, but the crystal structures are so tiny in their natural state that they aren't really visible, except as the familiar granules in your salt shaker. This experiment allows the salt crystals to adhere to one another on a porous surface, so that they create larger and more intricate crystal structures.

Liquid bluing is an inexpensive laundry whitener that helps speed crystal formation. It can be found online and at some stores.

Things You'll Need

4 tbsp iodized salt
4 tbsp liquid bluing
4 tbsp water
4 tbsp ammonia
Charcoal briquettes
Bowl
Large spoon
Vegetable ink (optional)

Instructions

Growing Your Crystal Garden
- 1
  Mix equal parts salt, bluing, ammonia and water in your bowl.
- 2
  Place your briquettes into your solution. The porous surface of the charcoal will help the crystals adhere to the briquettes. The solution should reach at least halfway up the briquettes, to ensure that the briquettes properly absorb the solution.
- 3
  Spoon your solution over your briquettes. You may also add several drops of vegetable ink directly to your briquettes to add color to your crystals. Experiment with a few colors for more interesting results.
- 4
  Wait six hours. You should see some signs of crystal growth, which will last for a few days.
- 5
  Mix small, equal amounts of bluing, ammonia and water, and pour this solution over your crystals after three days. This step will help your garden "live" longer. You may omit this step if you wish to end your experiment after three days.

Rocks & Minerals