It takes three days to complete. On day one, paint glue on the objects you want to grow crystals on. Then, sprinkle a little alum powder on the glue and let it dry overnight. Each alum particle acts as a seed for crystal growth.
The closer together they are, the less room your crystals will have to grow. This step requires adult supervision. Make sure all the alum dissolves it may still look a little cloudy and let the solution cool. After about 30 minutes, when the solution is cool enough to be safely handled, gently immerse your object in the alum solution. For color, you can add a large squirt of food coloring.
Let your project sit overnight to grow crystals. On day three, gently remove your object from the alum solution and let it dry. How does it look? Draw it or take a picture to put in your science notebook! Crystals are geometric networks of atoms. Certain crystals will only grow in certain shapes. For example, diamonds are always cube-shaped when they form. Whether the atoms have joined to form a small diamond, or a large one, it will always be in the shape of a cube!
Some crystals, like alum, will form from supersaturated solutions , like the one you used in this experiment. What else could you try? Could you do the same experiment with salt, or sugar crystals?
How do you think the color gets incorporated into the crystal? Do you think the food coloring disrupts the shape? Will larger crystals grow if you let your object sit in the solution longer? It only takes a spark to start a fire, and it only takes one atom to act as a seed for crystal formation.
Under the right conditions, the atoms in alum will join together like puzzle pieces to form large crystals. I posted a few years ago about how to grow a large alum crystal , but this experiment is even more fun. Alum is also called potassium aluminum sulfate. We made fake geodes by breaking eggs in half and washing them out, but we also encrusted a grape stem and a plastic shark.
It takes three days to complete. On day one, paint glue on the objects you want to grow crystals on. Then, sprinkle a little alum powder on the glue and let it dry overnight. Each alum particle acts as a seed for crystal growth.
The closer together they are, the less room your crystals will have to grow. This step requires adult supervision. Make sure all the alum dissolves it may still look a little cloudy and let the solution cool. Alum is found in the spices section of the grocery store. That little jar contains small white crystals that, with a bit of time and effort, grow a big alum crystal that looks a bit like a diamond.
It only takes about an hour to grow small alum crystals, but getting a big crystals takes days to weeks. All you need to grow alum crystals are alum, hot water, and a container. Choose a clear container so you can watch the crystals grow. While not strictly necessary, it helps having a way to tie and suspend a crystal in the liquid. This helps it keep an ideal shape. A coffee filter or paper towel keeps dust out of your project, while still allowing good air circulation.
There are actually a few different kinds of alum. The edible one in the grocery store is potassium alum. It grows clear crystals. Other types of alum include sodium, ammonium, selenium, and chrome alum. Chrome alum grows deep purple crystals. If you have access to the other chemicals, feel free to combine them to see what colors you get.
But, check the labels for safety information. Some types of alum are non-toxic, but others are irritants and not edible. The most common problem people experience growing alum crystals is that crystals not growing. If you don't see crystal growth within a day or two, there isn't enough alum in the liquid. Gently heat the liquid over a stove or in the microwave and try adding more alum powder.
Crystals only grow if the solution is saturated.
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