The paper presents an investigation on fundamental fracture modes of granite, using specific testing devices in order to highlight the salient features of fracture processes in granite such as path dependence (mode I tension fracture, mode II shear fracture and mode III torsion fracture), and shear transfers due to aggregate interlock (crack dilatancy), cross effect (frictional contact slip). Experimental results provided useful mechanical characteristics such as cracking strength, stiffness, toughness index and fracture energy according to the three basic fracture modes, and particularly the Hillerborg characteristic length of granite in tension readily derived from direct tension testing. In addition, computerized X-ray tomography analysis evidences localization of cracking in specimens subject to different fracture modes, readily detected by a non-linear analyser based on Volterra series expansion.