Development of effective mitigation strategies for handling solid wastes from oil shale production requires knowledge of the types and the distribution of organic and inorganic phases. Characterization of the mineral phases of a resource is essential in order to improve retorting efficiency and maximize recovery, as well to dispose of the waste in an environmentally safe manner. Nickel is one of the metals considered by the United States Environmental Protection Agency to be of primary environmental concern. In the sediments of the Green River Formation, abelsonite, a nickel porphyrin, has been encountered in the raw oil shale. Because of its organo-metallic structure, abelsonite, when thermally processed, would be expected to contribute virtually all of its nickel to the process waste materials. It is the potential increase in nickel concentrations in spent shale that merits the investigation of the distribution of this material. 40 refs., 6 figs., 4 tabs.