Sandstone is a sedimentary rock composed mainly of sand-size mineral or rock grains. Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in earth's crust. Like sand, sandstone may be any color, but the most common colors are tan, brown, yellow, red, gray and white. Since sandstone beds often form highly visible cliffs and other topographic features, certain colors of sandstone may be strongly identified with certain regions. For instance, much of the North American West is well-known for its red sandstones. Amherst, Ohio claims to be known as the Sandstone Capital of the World.

PHYSICAL PROPERTIES OF SANDSTONE & QUARTZITE
Color Minor color tonal variations exist but within the tolerance limit.
Hardness 6 to 7 on Moh's Scale Density 2.32 to 2.42 Kg/m3
Compressive Strength 365 to 460 Kg/m2
Water Absorption Not more than 1.0 %
Modulus of Rupture 197-200 Kg/cm2
Porosity Low to very low.
Weather Impact Resistant

CHEMICAL PROPERTIES OF SANDSTONE & QUARTZITE
Chemically they are very resistant Mono-Mineralic rocks, principally of silica.
SiO2 93-94%
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 avoids, alkalis and thermal impact. Insolubility in acids and alkalis is about 97%.