The use of scanning electron microscopy by secondary electrons permitted an analysis of the morphology of the silica gel particles. It was not possible to perform the analysis with silica suspended in the gel. Therefore, an analysis was performed with a kiln-dried sample that was manually ground in a porcelain mortar (Figure 5). In this case, the micrograph shows that individual silica grains could not be observed. Instead, the silica grouped into spherical clusters, forming an irregular and cohesive surface.