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Quarries
A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safety risks and reduce their environmental impact. The word ''quarry'' can also include the underground quarrying for stone, such as Bath stone. History For thousands of years, only hand tools had been used in quarries. In the eighteenth century, the use of drilling and blasting operations was mastered. Types of rock Types of rock extracted from quarries include: *Chalk *China clay *Cinder *Clay *Coal *Construction aggregate (sand and gravel) *Coquina *Diabase *Gabbro *Granite *Gritstone *Gypsum *Limestone *Marble *Ores *Phosphate rock *Quartz *Sandstone *Slate *Travertine Methods of quarrying The method of removal of stones from their natural bed by using different operations is called quarrying. Methods of quarrying include: *a) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bath Stone
Bath Stone is an oolitic limestone comprising granular fragments of calcium carbonate originally obtained from the Middle Jurassic aged Great Oolite Group of the Combe Down and Bathampton Down Mines under Combe Down, Somerset, England. Its honey colouring gives the World Heritage City of Bath, England, its distinctive appearance. An important feature of Bath Stone is that it is a ' freestone', so-called because it can be sawn or 'squared up' in any direction, unlike other rocks such as slate, which form distinct layers. Bath Stone has been used extensively as a building material throughout southern England, for churches, houses, and public buildings such as railway stations. Some quarries are still in use, but the majority have been converted to other purposes or are being filled in. Geological formation Bath Stone is an oolitic limestone comprising granular fragments of calcium carbonate laid down during the Jurassic Period (195 to 135 million years ago) when the regio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slate
Slate is a fine-grained, foliated, homogeneous, metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade, regional metamorphism. It is the finest-grained foliated metamorphic rock. Foliation may not correspond to the original sedimentary layering, but instead is in planes perpendicular to the direction of metamorphic compression. The foliation in slate, called " slaty cleavage", is caused by strong compression in which fine-grained clay forms flakes to regrow in planes perpendicular to the compression. When expertly "cut" by striking parallel to the foliation with a specialized tool in the quarry, many slates display a property called fissility, forming smooth, flat sheets of stone which have long been used for roofing, floor tiles, and other purposes. Slate is frequently grey in color, especially when seen ''en masse'' covering roofs. However, slate occurs in a variety of colors even from a single locality; for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dimension Stone
Dimension stone is natural stone or Rock (geology), rock that has been selected and finished (e.g., trimmed, cut, drilled or ground) to specific sizes or shapes. Color, Texture (geology), texture and pattern, and surface finish of the stone are also normal requirements. Another important selection criterion is durability: the time measure of the ability of dimension stone to endure and to maintain its essential and distinctive characteristics of strength, resistance to decay, and appearance. quarry, Quarries that produce dimension stone or crushed stone (used as construction aggregate) are interconvertible. Since most quarries can produce either one, a crushed stone quarry can be converted to dimension stone production. However, first the stone shattered by heavy and indiscriminate blasting must be removed. Dimension stone is separated by more precise and delicate techniques, such as diamond wire saws, diamond belt saws, burners (jet-piercers), or light and selective blasting wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China Clay
Kaolinite ( ; also called kaolin) is a clay mineral, with the chemical composition aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4. It is a layered silicate mineral, with one tetrahedron, tetrahedral sheet of silica () linked through oxygen atoms to one octahedron, octahedral sheet of Aluminium oxide, alumina (). Kaolinite is a soft, earthy, usually white, mineral (dioctahedral phyllosilicate clay), produced by the chemical weathering of aluminium silicate minerals like feldspar. It has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g). Rocks that are rich in kaolinite, and halloysite, are known as kaolin () or china clay. In many parts of the world kaolin is colored pink-orange-red by iron oxide, giving it a distinct rust hue. Lower concentrations of iron oxide yield the white, yellow, or light orange colors of kaolin. Alternating lighter and darker layers are sometimes found, as at Providence Canyon State Park in Georgia, United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
