Just when scientists thought they knew everything about crystals, a Northwestern University and University of Wisconsin-Madison collaboration has uncovered a hidden secret.

Centrosymmetric crystals are a special type of material that is fully symmetrical in every direction from a central point. Previously, scientists thought only non-centrosymmetric materials could exhibit chiral behavior—a property in which an object acts differently from its mirror reflection. But, for the first time, researchers have found a centrosymmetric crystal can act “chiral” despite its symmetry.

In the new study, published in Science, the research team investigated how a specific centrosymmetric crystal interacts with circularly polarized light, which twists like a corkscrew in either a clockwise or counterclockwise direction.