Recent surveys in the Neogene aeolianites of the Namib Sand Sea have led to the recovery of abundant and varied fossil eggshell fragments from diverse stratigraphic horizons: Aepyornithoid, Struthio and Diamantornis. The mineralogy, elemental composition, and organic matrices of these eggshells have been studied. Despite good preservation of the microstructural and mineralogical features of the fossil eggshells, the organic matrices have been altered in quantity and quality. The soluble and insoluble matrices of the eggshells show different behaviour during diagenetic processes.