The aim of the proposed experiment is to map the strain in quartz grains and its distribution in different regions of porcelain stoneware ceramics, in order to understand the post-firing failure mechanism caused by the accumulation of local stresses. This unwanted effect was observed in some industrial products after the introduction of new raw materials, with negative economic impact. To this aim a combination of x-ray tomography (XRT) and 3D x-ray diffraction (3DXRD) will be employed. From the analysis of the derived extensive datasets obtained from sound specimens and failing ones, we expect to understand the origin of the failure process and relate it to the raw material employed.