Introduction: Crystal Growth Project

About: MiniScience is a distributor of science education products, based in Clifton, New Jersey since the year 2000.

Growing crystals is not a long or complicated process. In fact, it's easy, fun and educational. In this example, we've dissolved Potassium Alum in water and within hours we'll be able to see sparkling crystals grow right before our own eyes.

Discover the laws of nature which creates crystals deep inside the Earth. Get a better understanding of how astronauts grow ultra-pure crystals in the weightlessness of space, and create your own collection of large crystals clusters, geodes and gem-like single crystals. A fascinating experience for children and adults!

Step 1:

Begin by making a saturated solution of Potassium Alum (salt). Dissolve 100 grams of the Alum in 500 mL of hot (near boiling) water. Slowly stir your solution until all of the crystals have dissolved.

Step 2:

Allow the solution to cool down (20-30 minutes). While you are waiting for your solution to cool down, this is a good time to prepare the string that the crystals will grow on.

Tip: We noticed that when we used a thin rubber band as a string, we were able to pull the crystal right out after it had formed the next day and therefore had a crystal specimen without any string or bands connected.

Step 3:

To give the crystal color, you can add some food dye/coloring.

Step 4:

When the saturated solution of Potassium Alum has cooled down to room temperature, carefully pour it into a clean beaker or glass making sure that no undissolved or crystallized salt gets transferred during the process.

We've used a coffee filter to make sure this process is done properly.

Step 5:

After transferring the solution and filtering all visible crystals, sit the dowel with string on top of your beaker or glass with the string immersed in the solution.

Step 6:

Cover the beaker with a napkin because crystals will form on practically anything that gets inside the cup.

Step 7:

As the water begins to evaporate, the salt will begin to form crystals on the string. It may take a few hours or even up to a day to see crystals so be patient and observe it periodically.

There are many factors, such as temperature, amount of Alum/Water used that will determine the size of the crystals. Test them out and see what crystals you can make! To purchase Potassium Alum, you can visit and type "Potassium Alum" in the search option.