Summer of Science: Grow Crystals

It's our first week of summer with all the kids at home and we've set a goal to do one cool science project a week as a family. We'd love for our readers to join us on this journey and experiment along with us! Science is cool, after all, and just because school is out, doesn't mean the learning stops at our house.

We wasted no time getting started on our Summer of Science and have spent this first week learning all about crystals. For our first science experiment, we tested out some crystal growing techniques. For variety, we tried out two different crystal growing recipes, one with a Magic Rocks kit (because I'm nostalgic for my childhood) and then also a home-made recipe using vinegar and salt.  

Grow Crystals with Magic Rocks Kit

I'm probably not the only one who had a blast with Magic Rocks as a kid. They're not technically crystals, but grow similarly and fairly quickly. Our youngest son kept calling it "his plant" and he was pretty on point as Magic Rocks are more like a chemical garden than crystals. The rocks that come with the kit are multi-colored in pink, green, yellow and blue. Kids get to gently break them into smaller pieces and divide them into three groups. The first group goes in a clear jar first, creating a stabilizing bottom layer. The kit comes with a growing solution that gets mixed with 12 oz. of warm water, then carefully poured into the jar. The second set of rocks goes in next, then after a few minutes, the third. It takes about four hours for the full effect of the growth to take place. My kiddos kept returning to the jar to check on crystal growth progress and they were amazed at the difference each time they looked. The chemical solution is definitely not edible, so close parental supervision is recommended on this one. 

Magic Rocks are made of metal salts that are dispersed in aluminum hydroxide.
The Magic Growing Solution is sodium silicate. 
Metal salts react with the Sodium Silicate to form chemical towers about 4 inches tall. 

Grow Crystals Using Salt and Vinegar

We started from scratch with our next crystal growing experiment with the following items:

  • 1 cup Hot Water, Boiling is Best
  • 1/4 cup Salt
  • 2 teaspoons Vinegar
  • Food Coloring
  • Medium Piece of Sponge
  • Shallow Dish

First, we stirred together the water, the salt and the vinegar. Then we laid the sponge on the shallow dish. Carefully, a kiddo poured the mixture over the sponge so that it soaked up most of the liquid with some in the dish, saving any extra liquid. Next, we dripped several droplets of food color on the sponge and sat the dish near a sunny window. About a day or so later we had some impressive crystal growth and the kids were fascinated.

Crystals All Around Us 

Crystals are everywhere and most of the time we don't even know it. The kids had fun guessing where we could find all kinds of crystals. We decided that sugar was made of crystals, which made for some tasty follow-up crystal experiment ideas, and then we set out to find how crystals form in the first place. We found this great, kid-friendly resource on how crystals work.

EJ Curran is a Delaware mom. This post is adapted from her blog, Four Little Monsters, at 


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