Sandstone is an sedimentary rock composed mainly of feldspar and quartz Iron oxides  silica sand matrix with quartz and varies in colour (in a similar way to sand), through grey, yellow, red, and white. beige, brown, tan, buff, ivory, pink, purple, yellow, gold, rust, cream. Sandstones are often relatively soft and easy to work which therefore make them a common building and paving material walls, cladding, beams and sills.