Here, guided by our previous experimental results, solubility calculations (Fig. ) and other studies we preselected an optimal window, indicated by the red rectangle Fig. , to produce bassanite via a simple and efficient cyclic synthesis method. Although various thermodynamic and applied aspects of this brine solution method have been reported in the literature , the actual conversion of gypsum to bassanite in brines has not been so far explored from the perspective of nano-scale mechanisms, which will be discussed in detail in the next sections.