Graphite (IMAGE) Deep Carbon Observatory Caption Used the world over in pencils, graphite is a mineral of pure carbon. The United States Geological Survey estimates over a million tons of graphite are currently mined every year around the world. Credit Smithsonian Digital Studios 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.