The paper briefly describes a possible application of X-ray computed microtomography studies followed by digital image analysis, enabling petrological assessment of carbonate rocks. The contribution presents an example of a complex, qualitative and quantitative approach aiming at deriving shape, geometry and spatial orientation of rock components as applied for a carbonate reservoir rock sample from the Zechstein Limestone (Ca1) strata. Apart from the basic properties of the analyzed objects, such as volume, surface area and number, detailed shape descriptors were obtained (compactness, sphericity, elongation, flatness, spareness). The presented approach allows for obtaining detailed 3D results at the microscopic scale, enabling extensive characterization of the studied material geometry. The methods proposed could be applied for other rock types as well.