In this paper, the contact angles between common minerals and water, n_heptane and n_butanol are reported. Seven common minerals, i.e., quartz, biotite, fluorite, pyrite, calcite, microcline and perthite, were polished and measured, and the surface free energies were calculated based on the Young's Equation. The results indicate that most of the crystalline planes are partially wetted by water and fully wetted by n-heptane and n_butanol. Furthermore, the heterogeneity between different crystalline planes is found, which could be attributed to the distinctive density of atoms of different elements as shown from the crystalline lattices. The data obtained and the viewpoint held in this paper will be helpful to understanding the interface process between the mineral and the liquid phase.