Although most of the Biyad-Wasi sandstones are friable and poorly cemented, some specimens reveal some cementation principally by secondary silica (or quartz), carbonate, or ferruginous material. The Biyad-Wasi sandstones have undergone several important diagenetic changes during their postdepositional history. The full paragenetic sequences commence with primary partial silica cementation, which was followed by precipitation of iron solutions in the remaining pore spaces; both these stages involved quartz overgrowths, produced as a result of pressure solution. Later stages resulted in precipitation of iron-rich clays and carbonate in new pore spaces created by partial replacement and corrosion of detrital quartz grains. The lack of quartz overgrowths is believed to be du to inhibition of pressure solution in these stages. The final diagenetic stages include weathering, which has created new pore spaces, and precipitation of silica dust (probably of aeolian origin) in such pores, and the formation of secondary silica overgrowths in the form of microcrystalline quartz. This process gives rise to the "quartzitic" crusts developed on many elevated outcrops of the Biyad and Wasi sandstones.

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