CRYSTAL-pp934adj-lg (IMAGE) Rice University Caption Black tourmaline going to pink tourmaline within a quartz pegmatite at California's Stewart Lithia mine. Credit Photo by Patrick Phelps/Rice University Usage Restrictions Must credit: "Patrick Phelps/Rice University" 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.