This cutting rig enables to test core and small block rock samples up to l0 x l0 x 20 cm in size. A piezoelectric force dynamometer and a computer based data acquisition system helps to record the three dimensional forces on the standard cutting tool. The specific energy calculated from the cutting force and the debris obtained from unit cutting length serves to classify the rocks according their cuttability and to have an idea about most suitable mechanical excavator for a given rock formation.