Serpentine (IMAGE) Washington University in St. Louis Caption The green mineral in this specimen from Washington University's teaching collection is serpentine. (Rocks that consist mostly of serpentine are called serpentinite.) The smooth surface on the sample is called a 'slickenside.' Credit Photo courtesy Jill Pateris 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.