The Growing Crystals Science Project – Fun & Learning

Growing Crystals Science ProjectThe Mystical World Of Crystals

Crystals hold an enchanted existence in the minds of children.

This growing crystals science project is not only a great visual experiment, it involves a very simple process that even younger children will find a lot of fun.

Parents looking to introduce their kids to science could do a lot worse than choosing this as their first foray into experiments.

One of the most popular ways to demonstrate crystal growth is by selecting either sugar or salt. Salt or sugar for a crystal project is a particularly good idea, especially with younger ones. Not only will they be able to observe the growth of crystal as they are formed, they can be used as either table salt or rock candy afterwards.

What Equipment Do We Need To Grow Crystals?

As with all our simple science experiments, it only requires a few items, readily available around your home.

As the sugar or salt solutions,  need to be brought to the boil, it is important that parents supervise and assist their children with this project.

For this experiment, we will concentrate on the more popular Rock Candy version of our project and we will need the following items.

  • Medium-sized jar
  • Medium-sized saucepan
  • Wooden spoon
  • Long enough length of cotton string to suspend inside the jar
  • Galvanized screw to keep the string held down inside the solution
  • Pencil, longer than the opening of the jar lid
  • 1 cupful of water
  • 2 cupfuls of sugar
  • Candy thermometer
  • Wooden spoon
  • Wax paper
  • Food coloring (if you want to make a variety of colored rocks)

Preparing For This Experiment

To begin our experiment an adult should first pour the water into the saucepan and bring the water up to boiling point.

Once the water starts to boil,  the sugar can be added gradually into the water, stirring continually. You need to stir the sugar and water together carefully until all the sugar has been absorbed by the water, creating a clear solution.

Onc the solution is clear, it means that all the sugar has mixed thoroughly with the water.

Now, it’s time for an adult to pour the solution into the jar. If you want to produce interesting and vibrant colored crystals, this is when you should add a few drops of your favorite food coloring.

Next, take the pencil and tie the string onto it, making sure that the end of the string is suspended an inch from the bottom of the jar. The pencil can be rested over the top of the jar lid opening and rotated to wind the surrounding string.

This is useful when trying to achieve the inch gap at the bottom of the jar.

Dip the string in for just a few minutes, before removing it from the jar and placing it on the wax paper. You now have to wait until the string has dried out completely and this could take some time. Once the string is completely dry, you then need to dip it into the mixture again.

A Bit Of The Science Explained – Why Dip The String?

Crystals will not be able to form on a string that has just been dipped into water and left. The reason for this is to give the chance for small crystal seeds to grow. Once the string is completely dry the small crystal seeds will provide a platform for larger crystals to grow.

Once completely dry put the string back into the solution, this is when new crystals will start to grow. As you put the string back inside the jar with the solution, you need to be very careful not to break any of the small crystals.

Watching The Crystals Develop With Kids

It is important that you do not disturb the string when you place it back inside the solution in the jar. Any movement could prevent the crystals from forming and cause them to break off. The best thing to do to avoid this happening is to put the jar somewhere neither you nor your children will be tempted to touch it.

Crystals can take anything from 7 to 10 days to develop, so think about the location carefully and urge your children to be patient.

Understanding The Why Behind The Experiment

When you heat sugar or salt in water until no more salt or sugar will dissolve, this is known as supersaturation. As a result, the water evaporates and crystals precipitate. This, in turn, causes the crystals to form on the seed crystals and the string.

Evaporation is, therefore, the catalyst, or process that causes the formation of crystals. As the water evaporates, crystals form, or as noted above, precipitate. The process continues until there is a balance between the water and sugar and salt from the original solution.

Try Different Versions Of This Experiment

As previously mentioned, with this grow crystals science project for kids, you can be a little versatile. Instead of sugar, for instance, you could use salt. Simply switch 2 cupfuls of sugar for 2 cupfuls of salt. You could also try adding a touch of flavor to the sugar crystals. Vanilla, strawberry lime and even orange essential oils all work well when added once the sugar has dissolved.

By adding flavor, you have not just helped to teach your children a valuable science lesson, but also created a tasty treat for them at the same time.

Safety Concerns

As this experiment involves the use boiling hot syrup; it should never be carried out without adult supervision and assistance. The last thing you want to happen while encouraging your children to enjoy science is for them to burn themselves. If you are experimenting with crystal growth with particularly young children, therefore, it is better that they are not in proximity when you are pouring the hot liquid into the jar.

Another potential safety concern you should be aware of is the jar itself. When pouring the hot solution into the jar, you need to make sure that the jar you choose to use is capable and recommended to hold boiling liquid.

If the jar you intend to use has not been rated for use with boiling water, let the water cool down for a few minutes, before pouring it into the jar. Using a thermometer is very helpful here. You want the water to be no higher than 125 degrees Fahrenheit before pouring it into the jar.

Obviously, the goal of this grow crystals science project for kids is to show them the importance of science, but that it doesn’t have to be something boring or too hard to understand.

Science can be fun as well as educational!






  • Melissa

    This is a great experiment, one I never heard of before. I can imagine how amazed children would be watching the crystals take formation. I will have to bookmark this for my daughter, she would love to do this for a science project. So these would be edible then?

    • Hi Melissa – Thank you so much for leaving a comment and really happy your daughter would like it. Yes, the crystals of salt and sugar are edible and safe for young ones.

      Typically, the sugar method is popular!

  • Oh wow, even as an adult I did not know you could do this. Really amazing experiment that I may even try for myself. I sometimes care for kids and may end up showing them this some time. Thanks for the interesting read

    • Hello Razzy – Glad you liked it. This one takes a bit of patience but great results as the crystals grow.

      Maybe we should start an adult science experiment site too?
      Thank you for the comment.

  • Hmm. Everyday I learn something new on the internet. Now it’s The grow crystal science project for kids. Thanks for explaining in very easy language and making it easy to understand.

    I will definitely try this out with my nieces. I would have to exercise caution not to get burnt though.

    Thank you very much for such a detailed review.

    • Thank you, Stunning Bell.
      Yes, you do need to be careful with this one due to the hot solution but the kids can get involved after that stage. The reward is in the growing of the crystals over a few days, so it’s a great one for reaching the importance of being patient.

  • My daughter loves these kind of projects. Can’t wait to try it with her. Not sure who will be more excited…me or her…haha. Thanks for posting!

    • Hi Kayla – Thank you for stopping by and taking the time to comment.
      This one takes a little patience but the results are worth it.
      Try some food coloring in the solution and you can make very interesting colored crystals.

  • Thank you for sharing such a great and informative article. As an adult even I am excited to do this! 🙂 I guess I will wait until I can do it with the kids.

    I absolutely loved the fact you kept repeating the safety aspect as this is something very easy to overlook.

    As a child at school we didn’t do many science experiments so I will be visiting your site often for more ideas to experiment with 🙂 Keep up the good work!

  • Pat

    I love that my children can actually come on this site and follow the experiments for themselves. I’ll be there with them, but it’s that easy to follow! Thank you for this. I will be using this as a resource when needed 🙂

  • My daughter sells makeup on the side. I’ll bet she probably would be interested in making some jewellery to sell on the side with some of her very own homegrown crystals. Definitely going to send her to this post.

  • wow, this is such an amazing article with lots of useful information. I will forward it to others as well. than you so much for sharing. My friends have school going kids and they love experimenting anything related to science, I will forward it to them and they will forward it to their friends for sure. Such a nice read, thank you.

    • Hi Sarah, thank you very much for taking the time to read my post and your kind words. I’m really pleased you enjoyed my post and I hope your friends enjoy the experiments too.

  • Hi Nick, we will have to try this experiment again. The first time we tried, this was a long time ago, we did not dip the string and let it dry. So we did not get any crystals to form. We were bummed out. Thanks for the great directions. I will let you know how it turns out the next time we try.

    • Hi Irene, Thank you for the feedback and I hope next time you get better results. Dipping the string and taking the time to let it dry is important. Without that start, the crystals will not have a stable platform to grow and grow! Please let me know if I can help in any way.

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