Standard dissolution experiments are carried out in stirred liquid. Therefore, the measured dissolution rate contains also diffusive and convective contributions, besides the desired surface reaction contribution. We present here a methodology, based on the hydrodynamical analysis of classical dissolution experiments, enabling us to extract the pure dissolution rate constant from the set of the already measured dissolution rates. The application of this analysis to the case of gypsum shows that the removal of the mass transport contribution from the dissolution rates of this mineral found in the literature brings, despite their apparent inconsistency, a coherent description of its dissolution kinetics and a well-defined value of its rate constant.