Sandstone

Type of sedimentary rock

Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains, cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar because they are the most resistant minerals to the weathering processes at the Earth's surface.

From Wikipedia, under CC BY-SA. More on occurri.