Selenium is of environmental concern due to a possible exposure of Se-79 radionuclide from a high-level nuclear waste repository to the biosphere or enlarged concentrations in soils and lakes or wetlands, threatening to health of vertebrates. Pyrite on the contrary is the most common iron sulfide on earth's surface and noted for the incorporation of trace elements into its structure. In this study, we report the development of a high temperature synthesis of pure selenium doted pyrite, using solid AlBr3, Fe-0, S-0 and Se-0 by means of a chemical vapor transport reaction in a 2-zone furnace with a gradient of 700 degrees C to 600 degrees C in a two reaction step. The amount of 1.1 wt% of homogeneously distributed selenium became incorporated into pyrite single-crystals with a size up to 0.5 cm in diameter. X-ray absorption fine-structure investigations were performed for the determination of the valence state and structural bonding of incorporated Se into pyrite. These reveal the predominant incorporation of Se-0 into pyrite structure without further bonding. This result indicates that the formation of a FeSxSey condensed matter, accompanied with a substitution of sulfur by selenium, is not likely. (C) 2012 Elsevier B.V. All rights reserved.