A discussion of the adsorption of inorganics from aqueous solution on inorganic adsorbents. It emphasizes the relationship between adsorption and surface charging, highlighting simple and complex adsorption systems sorted by the adsorbent as well as the adsorbate. The author includes a comprehensive collection of pristine PZC of different materials - covering crystallographic structure, methods of preparation, impurities in the solid, temperature and ionic composition of the solution, experimental methods to determine PZC, and the correlation between zero points and other physical quantities.