Sandstone

Sandstone is an arenaceous sedimentary rock composed mostly of feldspar and quartz and varies in colour, through grey, yellow, red, and white. Since sandstones often form highly visible cliffs and other rock formations, 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.
Sandstones are often comparatively soft and easy to work which therefore make them a common building and paving material.
Rock formations that are mainly sandstone usually allow percolation of water, and are porous enough to store large quantities, making them valuable aquifers. Fine grained aquifers, such as sandstones, are more apt to filter out pollutants from the surface than are rocks with cracks and crevices such as limestones or other rocks fractured from seismic activity.