Comminution tests are a vital element in the proper design of mineral processing plants. Several grindability tests have been developed over the years for different applications and each test has its strengths and weaknesses. Among test methodologies considered, is the universally accepted high-pressure grinding roller (HPGR) test procedures based on small-scale tests. The present work has been carried out to compare the grinding characteristics of different ore minerals. It was observed that all tested minerals, (quartz, chromite, marble, hematite, magnesite, dolomite) showed a general similar trend while being compressed. Moreover, because those minerals have wide differences in their mineralogical, physical, and mechanical properties they have different comminution behavior under compression. The consumed energy, as well as the reduction ratios, are affected by the mineral hardness. The percentage product at a certain cut-size was found to be proportional to the expended energy for each mineral. A convenient grindability index under compression has been suggested as the specific productivity, in ton/kWh. This index is quite sensitive to the material hardness.