Shapes of Snow Crystals (IMAGE) Purdue University Caption The unique shapes of snow crystals and the complex chemical reactions that occur on their surface could give clues about ground-level ozone loss. Credit Purdue University photo/Shepson Lab Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.