You can make your crystals different colors by adding food coloring. What happens if you mix your first batch one color and then add salt solution of a different color when the first batch has evaporated? Share your salt sculpture results on our bulletin board!

Compare the effects of heat and density on the diffusion of the food coloring. The diffusion will be much slower in the cold water. Try dissolving half a spoonful of salt in water and then drop the food coloring. The coloring will still diffuse, but it won’t sink because the saltwater has a higher specific gravity.

Here’s what to do:

1. Stir salt into boiling hot water until no more salt will dissolve (crystals start to appear at the bottom of the container).
2. Carefully pour the solution into your jar.
3. Suspend your string into the jar from the spoon laid across the top of the jar.

1. Place the salt into the sandwich bag.
2. Add two drops of food coloring.
3. Seal the sandwich bag and then shake and manipulate the salt inside so that the food coloring coats the salt crystals.
4. Unseal the sandwich bag to allow air in the bag.

Some crystals can be formed in an element named carbon. Nevertheless, all crystal form the same way, atoms come together and become a uniformed cluster. The process can take as little as a few days to maybe a thousand years. Natural crystals that come from the Earth form the same way.

Epsom salt grows into smaller, needle-like crystals and faster than table salt. You can buy it at a pharmacy. Alum salt grows quickly, sometimes making visible crystals within a few hours.

For the crystals to grow, it’s really important that the solution is saturated when the water is hot. Otherwise, the solution will not be supersaturated when it cools, and crystals won’t form (the background information to the project idea discusses this, if you want some more details).

No Crystal Growth This is usually caused by using a solution that isn’t saturated. The cure for this is to dissolve more solute into the liquid. Stirring and applying heat can help to get solute into the solution. Keep adding solute until you start to see some accumulate at the bottom of your container.

These crystals may take a few hours to a couple of days to grow. Quick crystals grow when the liquid cools quickly, as in a refrigerator. Chilling the liquid produces smaller, delicate-looking crystals. Refrigerating the liquid usually produces crystals within 30 minutes to a couple of hours.

Why does Epsom salt make crystal spikes? When you add Epsom salt to water, the salt dissolves. When you leave the pan in the sun, the water evaporates and the salt forms crystals shaped like long needles.

What You Do:

1. In the beaker, stir 1/2 cup of Epsom salts with 1/2 cup of very hot tap water for at least one minute.
2. Add a couple drops of food coloring if you want your crystals to be colored.
3. Put the beaker in the refrigerator.
4. Check on it in a few hours to see a beaker full of epsom salt crystals!

Process of Making Salt Crystals Fill your container halfway with warm water. Warm water helps to dissolve the salt quickly. Add a cup of salt to the warm water and stir it continuously until the salt is completely dissolved. Repeat the process until you cannot get any more salt to dissolve.

No chemical reaction takes place in this process, just dissolving and recrystallization aided by the bluing particles.