Abstract <p>This work proposes a methodology to characterize rocks by combining computed microtomography and X-ray diffraction techniques. Samples were extracted from rocks, and 3D images were subsequently captured. The same samples were used to obtain XRD diffraction patterns, and mineral identification in rocks was based on these patterns. Using the density of each mineral, 3D image processing enables its segmentation. Results show that the mineral distribution was random, without segregation, and that the volume fraction varied among samples despite their similar compositions. The isolated porosity had a volume fraction lower than 12%. It was also observed that carbonate formation on pore surfaces is linked to rock degradation, resulting from weathering and pollution. In conclusion, 3D imaging provides a valuable alternative for describing the microstructure and composition of rocks.</p> Graphical abstract <p></p>