what type of rock is sandstone

Sandstone is a sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. It is formed when grains of sand are compacted and cemented together over thousands or millions of years. The sand grains often consist of minerals like quartz or feldspar that were worn off other rocks and ground down into pebbles. Sandstone varies in color depending on the color of the sand grains it comprises or impurities it may contain. Outcrops in Kansas range from tan to orange to purplish red. Mineral grains in sandstones are usually quartz, but they can also contain significant amounts of feldspar, and sometimes silt and clay. The color of sandstone varies depending on its composition, and it can be gray to blue if it contains a significant amount of clay or silt.