The transformation of primary and secondary minerals in a recent shallow soil (Haplic Cryosol (Reductaquic)) from a highly weatherable ultrabasic rock (serpentinous dunite) of the mountainous tundra of the Polar Urals was determined. Primary and secondary mineral associations were analyzed in thin sections, by electron microscopy, X-ray diffraction, IR-spectroscopy, and thermal analysis. The susceptibility of the fresh rock for weathering was characterized by the micromorphology of the connective pores. Disintegration of the rock resulted in relatively high amounts of inherited olivine, serpentine, talc, and chlorite in the fine soil. Element release from fresh mineral surfaces exposed also in internal pore systems of rock fragments is a decisive factor for the appearance of secondary minerals in the fine soil. Secondary minerals are two smectites, saponite and nontronite, and vermiculite. Especially the silicates rich in Mg, olivine and serpentine with lower contents in the b1 mm fraction of the soil horizon