Although the size distributions are not very homogenous and smaller entities are also observed frequently, there seems to be an upper limit, which is well below 1 µm. These smaller entities are observed as "building blocks" for larger areas covered with solid materials when concentrations of solutions were increased. With respect to shape, there are also no welldefined structures observable, in general the single constituting entities appear rounded and flake-like in the AFM images. These experiments evidenced that there is an upper size limit for the aggregate sizes, which depends on the concentration and lesser so on the immediate incubation time after preparation. Most probably the size limit is defined by solubility of the aggregates, which crash out of solution after reaching a certain magnitude.