Fig. 2

Chemical stability diagram depicting the relative stabilities/equilibrium conditions (thick solid lines) of Mg(OH)2 (blue, line 8.1), ZnO (red, line 8.3), and Zn(OH)2 (black, line 8.4) as a function of pH and [M2+]. Included are trajectory lines (thin dashed/dotted lines) for various Mg–Zn pigments dissolving towards the Mn+/MX equilibrium conditions (line 1, for various Mg–Zn ratios). The composition of the Mg–Zn pigment affects the trajectory of the evolving solution chemistry. An inset is included which shows this effect in more detail for various Mg(x)–Zn(1 − x) alloy compositions