[en] Quarry tuffs are volcanic rocks made of an ash matrix with grain sizes ranging from fine clay minerals up to silt-sized material containing lithic, vitric and crystal clasts. They are mostly soft and porous rocks used as building stones. The aim of this work was to estimate the shielding characteristics of quarry tuffs using Monte Carlo methods and the XCOM code for 0.03, 0.07, 0.1, 0.3, 0.662, 1, 2, and 3 MeV mono-energetic photons. The relative transmission of Kerma in air, Ka, and the ambient dose equivalent, H*(10), was also determined. The main results follows. The linear attenuation coefficient of quarry tuff varies from approximately 2.290 to 0.065/cm for 30 keV to 3 MeV photons respectively. For 30 keV photons the half value layer of cantera is 0.3 cm and 10.7 cm for 3 MeV -rays. Photons with energy less than 60 keV are effectively stopped because the main interaction with cantera is through photoelectric interaction. Thus, the cantera is a good shielding material for rooms with X-ray units working below 60 kV. This X-ray equipment includes radio diagnostic X-rays for mammography