Fig. 4

Crystallisation of MgSO₄ from 1 °C to 50 °C and RH 15% to 98% computed by ECOS/RUNSALT. The colour shaded area represents the RH range of the solid form of the salts. The upper edge of the colour shaded area is regarded as the critical RH values of crystallisation. The dotted line represents the corrected crystallisation RH suggested by Steiger et al.³⁰.