gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1998.62A.1.28 Determination of Cu and Mo Isotope Fractionations in Natural Materials Using MC-ICP-MS Anbar D. Barling J. Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY 14627, USA Roe J. E. Dept. of Chemistry, University of Rochester, Rochester, NY 14627, USA 1998 62A 1 53 54 Copyright © 1998, The Mineralogical Society 1998