Roman Concrete Core Sample (IMAGE) University of California - Berkeley Caption Sample of ancient Roman maritime concrete from Pozzuoli Bay near Naples, Italy. Its diameter is 9 centimeters, and it is composed of mortar formulated from lime, volcanic ash and chunks of volcanic tuff. Credit Carol Hagen photo Usage Restrictions All rights reserved. Commercial use prohibited. 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.