OuR NaTuRaL StOnEs

Sandstone

shashank007 — Wed, 19 Nov 2008 05:58:15 +0000

Sandstone is a sedimentary bedrock composed mainly of sand-size mineral or bedrock grains. A lot of sandstone is composed of quartz and/or feldspar because these are the a lot of accepted minerals in the Earth’s crust. Like sand, sandstone may be any color, but the a lot of accepted colors are tan, brown, yellow, red, gray and white. Since sandstone beds generally anatomy awful arresting cliffs and added topographic features, assertive colors of sandstone accept been acerb articular with assertive regions.

Some sandstones are aggressive to weathering, yet are simple to work. This makes sandstone a accepted architecture and paving material. However, some that accept been acclimated in the past, such as the Collyhurst sandstone acclimated in the arctic of England, accept been begin beneath resistant, necessitating adjustment and backup in earlier buildings. Because of the acerbity of the alone grains, accord of atom admeasurement and friability of their structure, some types of sandstone are accomplished abstracts from which to accomplish grindstones, for cutting blades and added implements. Non-friable sandstone can be acclimated to accomplish grindstones for cutting grain, e.g., gritstone.

Rock formations that are primarily sandstone usually acquiesce aperture of baptize and are absorptive abundant to abundance ample quantities, authoritative them admired aquifers. Fine-grained aquifers, such as sandstones, are added apt to clarify out pollutants from the apparent than are rocks with cracks and crevices, such as limestone or added rocks burst by seismic activity.

limestone

shashank007 — Mon, 17 Nov 2008 06:17:04 +0000

limestone sedimentary rock wholly or in large part composed of calcium carbonate. It is ordinarily white but may be colored by impurities, iron oxide making it brown, yellow, or red and carbon making it blue, black, or gray. The texture varies from coarse to fine. Most limestones are formed by the deposition and consolidation of the skeletons of marine invertebrates; a few originate in chemical precipitation from solution. Limestone deposits are frequently of great thickness. The action of organic acids on underground deposits causes such formations as the Luray Caverns, the Carlsbad Caverns, and Mammoth Cave. Limestone is used as a flux in the extraction of iron, as an ingredient in Portland cement, as a source of lime

Granite

shashank007 — Wed, 05 Nov 2008 10:47:03 +0000

Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite has a medium to coarse texture, occasionally with some individual crystals larger than the groundmass forming a rock known as porphyry. Granites can be pink to dark gray or even black, depending on their chemistry and mineralogy. Outcrops of granite tend to form tors, and rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels.

Granite is nearly always massive (lacking internal structures), hard and tough, and therefore it has gained widespread use as a construction stone. The average density of granite is 2.75 g/cm3 and its viscosity at standard temperature and pressure is ~4.5 • 1019 Pa·s. The word granite comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a crystalline rock.

Chemical composition

A worldwide average of the average proportion of the different chemical components in granites, in descending order by weight percent, is

* SiO2 — 72.04%
* Al2O3 — 14.42%
* K2O — 4.12%
* Na2O — 3.69%
* CaO — 1.82%
* FeO — 1.68%
* Fe2O3 — 1.22%
* MgO — 0.71%
* TiO2 — 0.30%
* P2O5 — 0.12%
* MnO — 0.05%

Origin

Granite is an igneous rock and is formed from magma. Granitic magma has many potential origins but it must intrude other rocks. Most granite intrusions are emplaced at depth within the crust, usually greater than 1.5 kilometres and up to 50 km depth within thick continental crust. The origin of granite is contentious and has led to varied schemes of classification. Classification schemes are regional; there is a French scheme, a British scheme and an American scheme. This confusion arises because the classification schemes define granite by different means. Generally the ‘alphabet-soup’ classification is used because it classifies based on genesis or origin of the magma.

Marble

shashank007 — Mon, 03 Nov 2008 10:36:00 +0000

Marble is a nonfoliated metamorphic rock resulting from the metamorphism of limestone, composed mostly of calcite (a crystalline form of calcium carbonate, CaCO3). It is extensively used for sculpture, as a building material, and in many other applications. The word “marble” is colloquially used to refer to many other stones that are capable of taking a high polish.

Origins:–

Marble is a metamorphic rock resulting from regional or rarely contact metamorphism of sedimentary carbonate rocks, either limestone or dolostone, or metamorphism of older marble. This metamorphic process causes a complete recrystallization of the original rock into an interlocking mosaic of calcite, aragonite and/or dolomite crystals. The temperatures and pressures necessary to form marble usually destroy any fossils and sedimentary textures present in the original rock.

Pure white marble is the result of metamorphism of very pure limestones. The characteristic swirls and veins of many colored marble varieties are usually due to various mineral impurities such as clay, silt, sand, iron oxides, or chert which were originally present as grains or layers in the limestone. Green coloration is often due to serpentine resulting from originally high magnesium limestone or dolostone with silica impurities. These various impurities have been mobilized and recrystallized by the intense pressure and heat of the metamorphism.

HERE ARE VARITIES OF MARBLE STONE TO SEE THEM CLICK HERE

About Natural Stone

shashank007 — Thu, 30 Oct 2008 10:07:32 +0000

natural stone are the stone which are obtain beneath the earth surface.

there are many kind of natural stone like marble , slate, granite and many more .