The chemical constitution of sandstone is the same as that of sand, the rock is thus composed essentially of quartz. The natural cementing material that binds the sand together as rock is usually composed of silica, calcium carbonate, or iron oxide. Chemically sandstone is very resistant Mono-Mineralic rock, with silica as the principal. The percentage of each constituents is as follows:
Iron (Fe2O3) 1.5%-1.6%
Alumina (Al2O3) 1.4 to 1.5%
Soda (Na2O) & Potash (Kro) 1.0% to 1.2%
Lime (CaO) 0.8% to 0.9%
Magnesia (MgO) 0.2 to 0.25%
Loss On Ignition (LOI) 1.0% to 1.2%
They are highly resistant to acids, alkalis and thermal impact.