Detectable flashes of light are released as wintergreen-flavored candies are crushed in darkness.
Ingredients used to make wintergreen mints form a crystal that characteristically fractures across points in the molecular structure creating sheer planes that leave a negative charge (excess of electrons) on one side of each break and a positive charge (deficiency of electrons) on the other side of the break. A pulse of invisible ultraviolet (UV) light is generated as the excess electrons jump back as the candy breaks. That UV pulse excites molecules in the mint to emit a pulse of visible light.