Copper ingot (IMAGE) University of Gothenburg Caption Tobias Skowronek, German Mining Museum, in the process of sampling a copper ingot from the Skaftö wreck. Credit Staffan von Arbin, University of Gothenburg Usage Restrictions No restrictions. License Public Domain 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.