Microphotograph of NWA 7983 Ureilite (IMAGE) Proceedings of the National Academy of Sciences Caption Microphotograph of NWA 7983 ureilite showing areas of diamond and graphite surrounded by Mg-Fe-Ca silicate minerals Credit Image credit: Fabrizio Nestola and Oliver Christ. Usage Restrictions None 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.