Shark teeth, rich in fluorine (IMAGE) DOE/Oak Ridge National Laboratory Caption Shark teeth, rich in fluorine, were the first objects that ORNL scientists studied with their LIBS system, which can identify electronegative elements. Credit Jaimee Janiga/ORNL, U.S. Dept. of Energy Usage Restrictions None License Original 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.