Intact samples of coal have been analyzed by SIMS (secondary ion mass spectrometry) ion imaging and ion probe techniques for determination of the distribution of trace elements in pyrite and marcasite and in the associated clay minerals. Ion mapping of site-specific concentrations of trace elements is important as we consider ike environmental consequences of not only the combustion of coal, but also the disposal of coat-washing plant refuse and the placement of mine spoils during reclamation. Iron sulfides and clays are both involved in the oxidalion-nydralion reactions that result In the formation of acid waters and the release of trace elements into the ecosystem.