Bling, bling! UB chemist hosts national crystal-growing contest

BUFFALO, N.Y. — Move over, giant pumpkin growers!

Fall may be the season for mammoth pumpkin contests, but school kids nationwide are cultivating a very different kind of thing: crystals.

Organized by University at Buffalo researcher Jason Benedict, the United States Crystal Growing Competition starts Oct. 20. It challenges K-12 students and teachers to grow crystals made from aluminum potassium sulfate, a nontoxic chemical used in water purification and more.

The “biggest, nicest” crystals win, says Benedict, an assistant professor of chemistry.

The contest has the cachet of being sponsored by the American Crystallographic Association, which is based in Buffalo, as well as Ward’s Science and the UB Department of Chemistry.

The goal is to teach students about the science behind bling: What makes a crystal beautiful, and how to grow one.

“When you see this thing growing every day, it’s awesome. It’s so cool, and kids are just going to fall in love with this,” Benedict says.

He adds, “Crystals are really important to modern science. Everyone knows what a crystal is, and all of these technologies — from computers to pharmaceuticals — are based on crystals. But people know very little about them. We’re trying to change that.”

Benedict’s own research deals with sponge-like crystals called “MOFs” (metal-organic frameworks) that could one day be used to trap dangerous gases, sop up oil spills or soak up cancer drugs to deliver to tumors.

What: U.S. Crystal Growing Competition

Who: About 40 teams from dozens of locations nationwide, from Branch, Ark. to the Bronx and California’s Bay Area. Locally, the Dr. Charles R. Drew Magnet school and Charter School for Applied Technologies have participants.

When: Crystal-growing takes place Oct. 20 to Nov. 24. Judging is scheduled for early December.

Good visuals: Benedict has posted “How-To” videos showing how kids can grow great crystals: https://www.youtube.com/watch?v=dyo1RxGLIRY.

He will receive all the crystals in the mail in early December and lay them out in one location to be judged. The best will go on display in UB’s chemistry department.

Judges will be looking for qualities familiar to people who have shopped for a diamond ring; size, clarity and shape all matter. A good aluminum potassium sulfate crystal is colorless, transparent and octahedral (meaning it has 8 primary sides).

How to grow a great crystal:

Students will grow crystals by dissolving powdered aluminum potassium sulfate into water, then letting the water evaporate slowly. This causes the chemical compound to emerge from the solution and slowly form a crystal.

The trick to growing a big, beautiful 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 one large crystal.