Published October 20, 2017
National Chemistry Week starts on Oct. 22 this year, and to celebrate, kids across the country will grab beakers and begin growing crystals from a nontoxic chemical called aluminum potassium sulfate.
It’s all part of the U.S. Crystal Growing Competition. Now in its fourth year, the event challenges K-12 students and teachers to grow the biggest, highest-quality crystal. Winners receive prizes of up to $200.
“It’s going to be a lot of fun,” says contest founder Jason Benedict, associate professor of chemistry in the UB College of Arts and Sciences. “We’re really excited because the contest has basically doubled in size since last year.”
More than 160 teams have requested materials for 2017 — up from about 90 last year and 40 in 2014, the contest’s inaugural year. The 160 teams this year will include about 4,000 participants, as many teams include entire K-12 classes.
Benedict runs the competition with regional coordinators from the University of Central Florida, Georgetown University and Texas A&M University. UB students also help.
“I like how easy it is for younger students to get in on this. It’s a simple way to get them into science,” UB chemistry PhD candidate Eric Sylvester said earlier this week as he unfolded a mountain of postal boxes that will be used to ship free crystal-growing materials to participants.
A good aluminum potassium sulfate crystal is colorless, transparent and octahedral (meaning it has eight primary sides), and in past years, perfection in these areas made a winner.
Judges will be looking for these traits again in the contest’s “Best Overall” and “Highest Quality” crystal categories.
But a new prize class for 2017 adds a twist: Judges will also be picking the “Coolest Crystal.”
For participants, this can mean growing a funky-shaped crystal, trapping an object inside a crystal, or coloring crystals using dye or metal salts, or otherwise adding a creative flourish.
According to the contest’s official 2017 handbook, “Judges will consider originality, aesthetics and difficulty when determining the Coolest Crystal!”
Aluminum potassium sulfate, also called alum, is a nontoxic chemical used in water purification.
Students will grow crystals by dissolving powdered alum into water, then letting the water evaporate slowly. This causes the compound to emerge from the solution and slowly form a crystal.
The trick to growing a superb crystal is fine-tuning the evaporation rate: Let the water disappear too slowly, and the crystal will grow very slowly. Go too fast, and too much of the compound will crystallize, leading to imperfections called “occlusions,” or even to multiple crystals forming instead of a single large one.
Of course, these weird, imperfect crystals could be “Coolest Crystal” winners this year. Who knows?
The contest is sponsored by the American Crystallographic Association, the UB Department of Chemistry, the Western New York section of the American Chemical Society, Bruker, The Cambridge Crystallographic Data Centre, Krackeler Scientific Inc., the National Science Foundation and Ward’s Science.
Along with free crystal-growing supplies, all entrants will receive National Chemistry Week swag — including a pencil, pin and temporary tattoos — supplied by the American Chemical Society.