A significant weight loss of copper plate was observed after copper-water vapor interaction near critical point. This leads to the acceleration of the ceramic layer formation on SUS surface during granite-water vapor interaction in the presence of copper. In this paper, we have determined the chemical state of copper at which the mass transfer takes place through reaction with H-2 and O-2+N-2 gas mixture at the different 02 amount. Obtained results indicate that the weight loss of copper plate occurs at Cu2O (+1) state due to a complex processes. The morphology of copper species on the surface of mesh and granite suggests that the Cu2O was dissolved in water vapor and recrystallized on the surface of mesh and granite. Copper species were characterized by X-ray diffraction(XRD), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray (EDX). (c) 2006 Springer Science + Business Media, Inc.