Samples (IMAGE) Florida State University Caption Rock samples are purified to test for thallium isotopes at the National High Magnetic Field Laboratory. Credit Stephen Bilenky / National High Magnetic Field Laboratory Usage Restrictions Image may be used with approriate caption and credit. 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.