High-resolution X-ray computed tomography (HRXCT) is a nondestructive technique that allows exploration of the three-dimensional distribution of minerals and pore space in natural and synthetic rock samples. Recent technological developments allow the characterization of samples (up to few centimeters in diameter) at a resolution down to 0.7 μm. This, combined with the development of dedicated workflows, algorithms, and softwares, is opening new doors for the quantitative three-dimensional characterization of ores at the sample scale. When combined with three-dimensional image analysis, HRXCT provides quantitative three-dimensional mineralogical and textural measurements (volume, shape, three-dimensional relationship) that are impossible to assess accurately by any other method. This manuscript describes the principles of HRXCT and presents dedicated methodologies from data acquisition throught to quantitative three-dimensional measurements. These methodologies are applied to Ni-Cu-PGE ore samples but are suitable for a range of geologic materials. The combination of HRXCT with quantitative three-dimensional image analysis applied to geologic materials hosting ore deposits provides a better understanding of ore mineralogy, ore-forming processes, and parameters required for mineral or metallurgical processing, with benefit for both academic studies and mineral industry applications.