In the paper studies were presented which aimed at obtaining synthetic magnesium silicate, which could be applied as a selective adsorbent, polymer filler or a filler of paper-coating masses. Synthetic magnesium silicate was obtained by precipitation using solutions of MgSO4·7H2O and Na2SiO3 (water glass). In view of specific application of the precipitated silicates, the process of their production was broadened by introduction to the reactive system agents which hydrophobically transform silicate surface. Non-ionic surfactants were used for this purpose. The obtained products were subjected to a comprehensive physicochemical analysis. The tested parameters included bulk density, capacities to absorb water (wettability with water), dibutyl phthalate and paraffin oil, particle size distribution, and specific surface area. A significant element of the work involved studies on sedimentation of synthetic magnesium silicates, an important variable which determines directions of their application.