Sampling Locations and Concentrations of Rare Earth Elements (image) Tokyo Metropolitan University Share Print E-Mail Caption Samples were taken along rivers around Tokyo. Measurements of rare earth element quantities indicate a clearly elevated amount of gadolinium compared to that in natural shale. Credit Tokyo Metropolitan University Usage Restrictions None Share Print E-Mail 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.