Cross-sectional Map (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption In this cross-sectional map of the rod-shaped crystals that make up human tooth enamel, different colors indicate different crystal orientations. Credit Pupa Gilbert/University of Wisconsin 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.