Sponge Crystal Garden

Sponge Crystal Garden

In this experiment you will be exploring how crystals are made.

Crystals are formed when there is an excess of a solute in a solution.

A solution can be something as simple as salt (or sugar) mixed in water.

The solute is what we add to the solution (what is mixed in).

As the solution dries out the solute will go back to the way it was before it was dissolved. This means it will form bonds and become a solid.

In this case the solid will take the form of a beautiful crystal garden.

You Will Need:

  2-3 new dry Sponges
  Aluminum Tray (disposable)
  Measuring cups
  1/4 cup Salt
  1/4 cup Water
  (laundry section of supermarket) Liquid bluing
  2 tablespoons Ammonia
  Mixing bowl
  Metal spoon
  Food coloring

What To Do:

1. Put the sponges in the disposable pan.

2. Mix together the salt, water, bluing and ammonia.
*** Caution! keep face away from ammonia fumes.

3. Mix the ingredients well.

4. Pour the mixture on top of the sponges. Use the metal spoon to spread out the thicker material over the sponges.

5. Drizzle food coloring over the top of the sponges in random patterns.

6. Leave the sponges in the tins to create crystals in a few days.

How does it work?

The experiment works because the mixture allows for the seeding of crystals. The sponges serve as a medium for the crystals to grow. The crystals will continue to grow until they run out of material to make new ones!


1. Can this experiment work with sugar and not salt?

2. Will this work if we use something other than a sponge?

3. Would a crystal grow faster if seed crystals (like sugar) were used on the starting material?