The purpose of this paper is the determination of the fracture mechanical characteristic values of granite and sandstone samples using the wedge splitting test according to E. Tschegg. The wedge splitting test is one of the most common techniques used for the determination of the fracture mechanical characterization of heterogeneous materials under crack mode I. The specific fracture energy and the nominal notch tensile strength will be calculated directly from the testing and the tensile strength has to be ascertained inversely. The results gained from the experiments will be implemented in ABAQUS, a finite element analysis software. Further, the results will be used for the creation of a set of representative material parameters for granite and sandstone. For reasons of verification, the numerical and experimental results will be compared with the results of direct tensile tests and Brazilian tests.