In this research, malachite particles with different roughness values were produced by grinding malachite sample together with quartz (mohs hardness: 7) and montmorillonite (mohs hardness: 1-2), respectively. Micro-flotation results showed that higher recovery was achieved by using malachite particles of higher surface roughness as feed. The contact angle measurements demonstrated that the contact angle of natural malachite surface decreased with the increase of its surface roughness, while the contact angle of malachite conditioned with 5 x 10(-5) mol/L sodium oleate increased with the increase of its surface roughness. It might be concluded that grinding media can influence minerals surface roughness, thus affecting the wettability of their surface and, consequently, the flotation performance.