In this study, a series of characterization analyses were performed on both uncoated commercial calcites and commercial calcites modified via hydrophobic coating with stearic acid (SA); the effect of the coating process on specific physical properties (particle size distribution [PSD], BET surface area, porosity, bulk (or free flowing) density, and moisture content) and surface properties (water contact angle [θwater], surface free energy [SFE], and zeta potential [ZP]) was investigated in detail. The commercial calcites used in the studies are Ground CaCO3, GCC, Nidascarb 70; SA-coated/modified GCC; M-GCC, Nidascarb 70T; Precipitated CaCO3, PCC, adaCAL N1, and SA-coated PCC; M-PCC, adaCAL N1C. The results showed that the hydrophobic coating process reduced the particle size of both products (GCC and PCC), but this reduction was more pronounced in fine particles. At the same time, it decreased and disappeared in coarse particles. One of the most striking results concerned surface area: the coating process increased the surface area of GCC, thereby decreasing the surface area of PCC, owing to PCC's porous aggregate structure composed of nano-cubic/rhombohedral crystal grains. It was determined that the total pore volume of PCC decreased from 1.04 cm³/g to 0.83 cm³/g after the coating process. According to θwater data, the hydrophobic character of M-GCC (128.9°) was found to be higher than that of M-PCC (94.3°). Hydrophobic coatings significantly alter not only the surface properties but also the physical properties of both natural (GCC) and synthetic (PCC) calcites.