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Sandstone

A sedimentary rock formed by the consolidation and compaction of sand and held together by a natural cement, such as silica. It usually has quartz in it. Grains of sand are weathered, which means blown around by the wind, or pushed around by rain, water, or erosion. When it settles down in one place, it forms layers that are stuck together with the minerals that fall between the grains of sand.

Sedimentary rock formed from sand-sized grains (0.0025 – 0.08 in., or 0.06 – 2 mm, in diameter). The spaces between grains may be empty or filled with either a chemical cement of silica or calcium carbonate or a fine-grained matrix of silt and clay particles. The principal mineral constituents of the grain framework are quartz, feldspar, and rock fragments. Sandstones are quarried for use as building stone. Because of their abundance, diversity, and mineralogy, sandstones are also important to geologists as indicators of erosional and depositional processes.

Sandstone is mined using quarrying. Sandstone is sometimes found where there used to be small sea areas. It is formed in deserts or dry places like the Sahara Desert in Africa. In the western United States, most sandstone is red. It can also be found around lakes, rivers, deltas, and shores all over the world.

Material Notes:

Sedimentary rock composed of cemented sand grains. Its critical mineral is quartz (50-100%); feldspar and calcite may also be present in the sand grains. Commercial types include quartzite, bluestone, brownsytone, and freestone. Sandstone rocks are sedimentary rocks made from small grains of the minerals quartz and feldspar. They often form in layers as seen in this picture. They are often used as building stones. Sandstone retains only a small part of the intergranular pore space that was present before the rock was consolidated; compaction and cementation have greatly reduced the primary pore space.

Secondary openings, such as joints and fractures, along with bedding planes, contain and transmit most of the ground water in sandstone. Accordingly, the hydraulic conductivity of sandstone aquifers is low to moderate, but because they extend over large areas, these aquifers provide large amounts of water.

Most of the sandstone quarried in Arkansas is crushed and used for aggregate in concrete and asphalt. Large blocks (riprap) are used for fill and in dike and jetty construction. Rough, weathered sandstone blocks and boulders (fieldstone) have been used for years as facing stone on homes and other buildings, and to build other structures such as fireplaces, walls, and walkways. Much flaggy sandstone has been produced from the Hartshorne Sandstone (Pennsylvanian) near Midway in Logan County. Other counties in west-central Arkansas that occasionally produce this type of material are Logan, Sebastian, and Franklin. A substantial tonnage of thin flagstone and dimension stone has been produced in the state since the early 1950’s. A large quantity of natural or rough fieldstone used for rustic construction is obtained from bouldery talus and alluvial deposits throughout the Interior Highlands of Arkansas.

Sandstone is used in countertops, tiles, concrete, play sand, glass filing, polishing metal, sandblasting, and in making buildings.

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