Stromatolites (IMAGE) University of Colorado at Boulder Caption Hynek used a rock hammer to crack open a stromatolite formation, revealing its pink center. More stromatolites grow under the water nearby. Credit Brian Hynek Usage Restrictions Use with credit only 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.