Values of points of zero charge are indicators for the intensity of interactions of minerals with protons (hydroxyls) in aqueous suspensions and indicate whether a solid is acid or basic. As such they influence many important features of the particles like suspension stability, adsorption behaviour, catalytic properties etc.

Definitions for different points of zero charge are presented. Predictions of pristine points of zero charge based on various models are addressed. In this respect experimental methods to determine points of zero charge of minerals, which are the basis for model development and validation, are shortly described. Among others, experiments covering traditional approaches such as potentiometric acid-base titrations, electrokinetic methods or suspension stability studies as well as modern surface force measurements are available. The possibilities as well as the respective problems inherent to the methods themselves but also in the interpretation of the experimental raw data are shortly discussed.

Results from different computational approaches covering Parks` model and the subsequent refinements and first principle applications are discussed.

Published comparisons between experiment and model are critically reviewed and the importance of assessing the experimental data used in the comparisons is stressed.

The effect of temperature on points of zero charge is shortly addressed.