The analysis by X-ray diffraction of a mining sample collected from Oshno hill, which is located in the District of Chavín de Pariarca, Huamalies Province, Huanuco, Peru, indicates the presence of lepidocrocite (γ-FeOOH) and goethite (α-FeOOH). The room temperature Mössbauer spectrum (MS) doublet with broad lines displays hyperfine parameters corresponding to the presence of particles of iron hydroxides smaller than 100 Å in a superparamagnetic regime. The measurement of a MS at 4.2 K allowed confirming the presence of goethite and lepidocrocite (with average magnetic fields of 49.21 T and 44.59 T, respectively). © Springer Science + Business Media B.V. 2009.