Laboratory experiments using Raman imaging demonstrated the behaviour of ZnSO₄⋅7H₂O (goslarite) microparticles in contact with a 1014 CaCO₃ (calcite) surface under three different experimental conditions representative of remote atmosphere. Contact between the ZnSO₄⋅7H₂O particles and the CaCO₃ surface in humid air (RH ~40-80%) did not induce any deliquescence and chemical phenomena. In contrast, condensation of a water drop at the ZnSO₄⋅7H₂O-CaCO₃ interface caused free dissolution of the ZnSO₄⋅7H₂O particle and rapid precipitation of Zn₄SO₄(OH)₆ onto the CaCO₃ surface. This coating inhibited the surface reaction and subsequent drying resulted in the deposition of residual ZnSO₄⋅7H₂O, then ZnSO₄⋅H₂O (gunningite) and CaSO₄⋅2H₂O (gypsum) superimposed onto the Zn₄SO₄(OH)₆ layer. The deposition of ZnSO₄⋅7H₂O particles in a water drop, previously in contact with a CaCO₃ particle for a long time, resulted in the coprecipitation of Zn₄SO₄(OH)₆ and Zn₅(CO₃)₂(OH)₆ (hydrozincite). Subsequent drying caused the deposition of residual ZnSO₄⋅7H₂O, ZnSO₄⋅H₂O and CaSO₄⋅2H₂O as small particles. These results indicated the possible fates of ZnSO₄ particles in a humid atmosphere, when externally mixed with CaCO₃ mineral dust after atmospheric events such as aggregation, water condensation and evaporation. This study indicated the fundamental role of water that typically existed on the surface of aerosol particles in the troposphere. These heterogeneous chemical processes have substantial consequences on particle size and solubility, and thus on bioavailability and toxicity of metal-rich particles.