Want to have some mildly traumatic fun with your kids? Be a sideline parent while they work on a science fair project. My son had one due for his fourth grade class — I nearly had a coronary. I have mild OCD and had to fight the urge to perfect everything or “do it the right way.” It took all of my efforts (and my husband’s threat to duct tape me to a chair) to assist him only as needed. The upside, when he was all done, was that I got to play with stuff and make this post!
His project was a lot of fun, too, and gave us things to do as a family. He was testing the effects of temperature on crystal growth, and that meant growing some crystals. This was actually pretty easy, and there are many ways to try it. The two most interesting crystals we grew as a test were from alum powder and epsom salts. The alum grew hexagonal shapes, and the epsom grew spikes. Alum powder runs about $4.00 at the grocer, but it really needs to be the fine ground, sand quality. The epsom salt (not pictured) is about $1.50 for a quart sized carton.
**Note: We tried a bulk jar of alum powder that was more coarse and it did not work at all.**
- alum powder (small jars sold in spice section)
- epsom salt
- large mason jar
- small glass jar (baby food or small votive work well)
- water (near boiling)
- heat lamp (optional)
Making Crystals from Alum
- Start 600mL of water to heat.
- Dump entire container of alum powder into large mason jar
- Pour hot water into jar and mix until all dissolves.
- Pour approximately 3 tbsp or solution into the small jars and set the remainder aside.
- If you have a heat lamp available, put the jars under the lamp, and you will see large crystals by the next morning.
Making Crystals from Epsom Salts
- Heat 2 cups of water to near boiling.
- Pour carefully into small jar.
- Add salt until no more will dissolve.
- Place jar in safe spot in the refrigerator.
- You should have spikey crystals visible within 24-48 hours.
- They will grow larger as the solution evaporates.
Both of these can be used to make your own personal geodes at home, as well. This requires eggshells cut in half and thoroughly cleaned. If you are using fresh eggs, a good washing and drying will be enough. Store bought can require a hot water bath. Follow the same steps, but instead of a jar, pour solutions into shells.
Science fun facts we learned from the Smithsonian Natural History Museum:
- Crystals get their shapes from the atoms linking together in identical, repeating patterns.
- Color is determined by what color of the light spectrum is NOT absorbed by the minerals the crystal is made of.
- Crystals can stop growing, dissolve, then start again!