gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1998.62A.2.10 Geochemical Study of the Microbial and Inorganic Precipitation of Magnetite and Siderite at Low Temperatures Horita J. Cole D. R. Chemical and Analytical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Zhang C. Phelps T. J. Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Liu S. V. Department of Microbiology and Immunology, Allegheny University of the Health Sciences, Philadelphia, PA 19129, USA Valley J. W. Department of Geology and Geophysics, University of Wisconsin, Madison, WI 53706, USA Hayashi K.-I. Institute of Mineralogy, Petrology, and Economic Geology, Tohoku University, Japan 1998 62A 2 651 652 Copyright © 1998, The Mineralogical Society 1998