Sandstone

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.

thumb|Niapiskau island, limestone monoliths, Gulf of St. Lawrence, [[Mingan Archipelago National Park Reserve, Canada]] thumb|Uluru, [[Northern Territory, Australia, is often referred to as the biggest monolith. While the surrounding rocks were eroded, the rock survived as sandstone strata making up the surviving Uluru 'monolith'.]] thumb|Monolithos, Greece|Monolithos fortress on [[Rhodes, Greece]] thumb|Landsat 7 image [[Brandberg Mountain, Namibia]] thumb|Pedra da Gávea|Gavea Rock, a monolith next to the sea, near [[Rio de Janeiro, Brazil]] A monolith is a geological feature consisting of a

thumb|West and East Mitten Buttes|The Mittens and [[Merrick Butte in Monument Valley, Utah–Arizona]]

thumb|right|Photomicrographs of feldspathic (L) and lithic (R) greywacke. The top images are in Plane polarized light|plane-polarized light; the bottom images are in [[cross-polarized light. Cements fill the pore spaces.]] thumb|Closeup of Pharaoh Menkaure's greywacke statue, 25th century BCE, from the [[Egyptian Museum in Cairo]]

Arkose () or arkosic sandstone is a detrital sedimentary rock, specifically a type of sandstone containing at least 25% feldspar.

fragment of a large sandstone slab which originally stood at the mouth of the Singapore River, now in the National Museum of Singapore

thumb|Portage Park (Chicago)|Portage Park in [[Chicago is known for its flagstone decorations.]]

300px|thumb|right|The Salt Cellar, a gritstone Tor (rock formation)|tor on [[Derwent Edge in the Peak District, England]]

thumb | right Psammite (Greek: psammitēs "(made) from sand", from psammos "sand") is a general term for sandstone. It is equivalent to the Latin-derived term arenite and is commonly used in various publications to describe a metamorphosed sedimentary rock with a dominantly sandstone protolith. In Europe, this term was formerly used for a fine-grained, fissile, clayey sandstone. Pettijohn gives the following descriptive terms based on grain size, avoiding the use of terms such as "clay" or "argillaceous", which carry an implication of chemical composition:

geographical object

thumb|A photograph of a slab of Itacolumite Itacolumite is a naturally occurring sandstone that is flexible when cut into relatively thin slabs. It occurs at Itacolomi, its eponym, in the southern portion of Minas Gerais, Brazil. The stone is porous, and often yellow in color. It is also found in Kaliana village (Charkhi Dadri district, Haryana, India), the U.S. state of Georgia, and Stokes and McDowell counties of North Carolina. It is the best and most widely known example of a flexible sandstone, and is a source of diamonds found in the Minas Gerais area of Brazil.

thumb|Arenite

thumb|Greensand (glauconitic sandstone) alt=This image shows a rock and the occurrence of glauconitic siltstone in the Serra da Saudade ridge, in the Alto Paranaíba region, Minas Gerais state, Brazil.|thumb|Occurrence of glauconitic siltstone in the Serra da Saudade ridge, in the Alto Paranaíba region, [[Minas Gerais, Brazil]] Greensand or green sand is a sand or sandstone which has a greenish color. This term is specifically applied to shallow marine sediment that contains noticeable quantities of rounded greenish grains. These grains are called glauconies and consist of a mixture of mixed-la

thumb|300x300px|Brownstones in Harlem, Manhattan, New York City 300px|thumb|Biking among brownstones in Park Slope, Brooklyn Brownstone is a brown Triassic–Jurassic sandstone that was historically a popular building material. The term is also used in the United States and Canada to refer to a townhouse clad in this or any other aesthetically similar material.

sedimentary rock