Graphene (image) University of Arizona Caption Graphene trilayers can be stacked in two different configurations, which can occur naturally in the same flake. They are separated by a sharp boundary. Credit Pablo San-Jose ICMM-CSI Usage Restrictions This visual may only be used in conjunction with reporting/posting of this news release. Image/video credit must be included exactly as indicated. 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.