Figure 5. Schematic representation of the four stages of CaSO₄ formation.

(a,b) As observed for our experimental conditions: (stage I) formation of well-defined, sub-3 nm primary species/scatterers; (stage II) formation of domains of primary species; inset shows that scatterers are on average separated by a distance of 2<R_eHS>; (stage III) aggregation and self-assembly of the primary species forming large surface fractal morphologies; (stage IV) growth and coalescence of the primary species within the aggregates; insets in c and d show the consequent stages of growth—increase in length followed by increase in all dimensions eventually leading to larger morphologies.