The Sandstone is composed of mineral grains, organic material and rock. It also consists of some special cementing agent to keep the sand grains attached, along with clay or silt sized particles to fill the gap between the grains. It is one of the best known rock and can be found widely spread all over the earth’s crust. The other synonym is Arenite and it is generally composed of Feldspar or Quartz, which are the commonly found minerals under the Earth’s crust. It is found in a wide variety of colors like red, yellow, tan, pink, gray, black and white.
The sand in the sandstone is a grain sized mineral that ranges from 1/16 mm to 2 mm in diameter. This sandstone is generally mined for the construction work or in the manufacturing sector as a raw material.
The Sandstone is composed of many minerals and rock grains under the crust. It is believed that those rock and mineral grains were once a part of some other rock. Hence it can be assumed that every mineral, especially the rock forming will become a sandstone ingredient, at least once. Very rarely found minerals in the sandstone are Amphiboles and Pyroxenes. Feldspar is a very common mineral; hence it is found in the composition of the sandstone, but in a low proportion. The sandstones that possess Feldspar above 25% are referred as ‘Arkose’. The other commonly found ingredient is the Quartz. It is a very common mineral found in rock formations. It is physically very strong, hence insoluble in liquid. This characteristic makes it more available in the sand. The sandstones that exclusively form with quartz grains is referred as ‘Quartz Arenite’. Mica is the other commonly found mineral in the rock formation. It has an important part in the formation of micaceous sandstones.
As the name implies, sandstone is composed of sand like structures that ranges between 0.1 mm to 2 mm in size. If the grains are smaller, then, it is composed of either siltstone or shale, and if the grains are a bit larger, then, it consists of breccias or conglomerate. The cementing agent can alter the characteristics like porosity, usefulness and color of the sandstone. Mostly the cementing agents found are quartz (silica), gypsum, calcite and clay. The sandstone with silica as a cementing agent is very hard and durable. The sandstone with calcite as a cementing agent can be easily eroded and can undergo acidic dissolution. Gypsum and clay cements, being a soft mineral, can form sandstone with the similar characteristic. The colors differ depending on the contents of the sandstone. Manganese oxides, iron oxides and impurities give bright colors to the sandstone. The ornamental desirability and unique character of the sandstone is because of its attractive colors. The commonly found sandstone colors are white, green, purple, red, orange, yellow and sometimes black. The texture of the sandstone depends on the layer of sand having different characteristics. The gradual formation of layers with different types of sands causes the banding in the sandstone.
Since ancient times, sandstone was popularly used in House ware and construction, and is still used for the same purpose. It is a common building material and is used to construct homes and temples. Artists make use of sandstone to make ornamental statues and fountains. Some types of sandstone are used to make grindstones, useful for increasing the sharpness of blades and other equipments. Grinding stone for grains are also made out of sandstone.