Growing crystals can be done with various substances such as sugar or borax. These can seem magical to children with the transformation involved. Growing crystals is good step for learning chemistry, geology, or semiconductors.
Safety note: Be sure to explain safety precautions to children. These experiments use chemicals and heat. Eye and heat protection should be used. Before and after this experiment, be sure to thoroughly clean hands. Disclaimer: All information provided on this site is for entertainment and education purposes only. Using any information from thecasabouquet.com is at your own risk.
The basic set up for growing crystals science project is heating water and dissolving the crystal chemical until a saturated solution is achieved. Something has to be used for the crystals to grow on, often a pipe cleaner, cotton string, or stick (substrate). A seed crystal may need to be provided, such as rolling a wet stick in sugar and letting it dry. The substrate may be hung in a container of solution, allowing it to evaporate overnight or longer while the crystals grow. These 8 growing crystals projects encourage children to ask questions about solutions and crystal structure, collect data, analyze, and share their findings.
- DIY crystal geodes in eggs from Sweet Paul
- How to make crystals with borax and pipe cleaners from Kids Activities Blog
- Sugar crystal ornaments from Steve Spangler Science
- Magic crystals (Epsom salts) from Bitz N Giggles
- Salt crystal garden from Wayne Schmidt
- Overnight crystal garden (Epsom salts) from Babble Dabble Do
- How to make crystal geodes from Feels Like Home
- How to grow aragonite crystals from TinkerLab
When trying a growing crystals science project, I always encourage children to make it into an experiment. There are several areas where variables can be changed.
String: provide cotton, sisal, jute, and nylon. Try smooth string, string that’s been roughened (use sandpaper), and string that’s been wet, rolled in the original chemical, and dried. Do pipe cleaners, sticks, or strings work best?
Temperature: try a freezer, a refrigerator, or a sunny windowsill. Should the saturated solution be cooled down slowly or quickly?
Seed crystal: Does your substrate work with or without a coating of the original chemical? How much is needed?
Evaporation: how does the evaporation of the water affect the crystal growth? Cover the container with plastic wrap, blow a fan over the container or put it in a fume hood, place the container in a warm place or a cool place.
Crystal structure: provide marshmallows or spice gumdrops and toothpicks to build models of different crystal structures. Build face-centered cubic, body-centered cubic, and hexagonal close packed. Which familiar substances have these structures?
Affiliate links: if you make a purchase using these links, I’ll receive a small compensation towards maintaining this blog, at no extra cost to you.
- Borax, alum, Epsom salts
- Candy sticks, skewers
- Cotton string
- Pipe cleaners
- Plastic eggs
- Distilled water
- 4 cup pyrex
What is the science?
Content: solutions, saturated, crystallization, Le Chatelier’s Principle
Circuits in semiconductor chips are a dominant part of modern life. And those chips start off with making crystals of silicon or other semiconductors. Computer chips, the IGBT (insulated gate bipolar transistor), LEDs, and solar panels are just a few of the devices built upon the original development of silicon wafers. They are found in CFL and LED light bulbs, coffee makers, refrigerators, cars, phones: the list goes on and on.
Atoms of a solid usually are organized into crystals. Ice, metals, and diamonds are all crystals. Crystals are an important part of chemistry and geology.
A solution is a liquid (solvent) with a solid (solute) dissolved in it. A saturated solution has all the solute it can hold – one more bit would fall to the bottom. A super saturated solution can be made by heating, which allows more solute to dissolve. As this cools, it can crystallize very easily.
- General Lab Safety resources from Flinn Scientific. Be sure to check out the Student Safety Contract.
- Egg geodes experiment from TinkerLab
- Silicon wafer animation. YouTube video from Silicon Valley Technical Institute
- The Science of snowflakes from PBS Science Thursday
- Crystal systems from Crystal Age
- Unit cells from Purdue Chemistry
- Types of saturation from UC Davis
Let’s talk story
I like doing these labs with children, but they are hard from a classroom management perspective. Growing crystals can take days, or even weeks, and the delayed gratification may not work well in the classroom.
I loved growing crystals in my undergraduate analytical chemistry class. I had grown a gorgeous large crystal, which was quietly living and growing in my lab drawer. Our lab was in a very old building in the South. Imagine my horror when I came to lab to weigh my results and get my grade, and a large critter was lying there in my drawer instead. He had eaten my crystal and died as a result. Fortunately, my instructor allowed me another chance to grow a crystal and get my grade.
I’ll be looking for comments below, or contact me at lisa [at] thecasabouquet[dot]com.