Information AboutSand |
| CATEGORIES ABOUT SAND | |
| granular materials | |
| pedology | |
| sediments | |
| sedimentology | |
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Sand is a Granular Material made up of fine mineral particles. It is a naturally occurring, finely divided Rock . Sand comprises particles, or granules, ranging in , where size in Φ = -log base 2 of size in mm. On this scale, for sand the value of Φ varies from -1 to +4, with the divisions between sub-categories at whole numbers. CONSTITUENTS OF SAND The most common constituent of sand, in inland continental settings and non- Tropical coastal settings, is Silica (silicon dioxide, or SiO2), usually in the form of Quartz , which, because of its chemical inertness and considerable hardness, is resistant to Weathering . The composition of sand is highly variable, depending on the local rock sources and conditions. The bright sand dunes of the White Sands National Monument in New Mexico are famous for their bright, white color. Arkose is a sand or Sandstone with considerable Feldspar content, derived from the Weathering and Erosion of a (usually nearby) Granite . Some sands contain Magnetite , Chlorite , Glauconite or Gypsum . Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and Obsidian . Chlorite-glauconite bearing sands are typically green in color, as are sands derived from basalt ( Lava ) with a high Olivine content. Many sands, especially those found extensively in Southern Europe , have Iron impurities within the quartz Crystals of the sand, giving a deep yellow colour. Sand deposits in some areas contain Garnet s and other resistant minerals, including some small Gemstone s. Sand is transported by wind and water and deposited in the form of Beach es, Dune s, Sand Spits , Sand Bars and related features. STUDY OF SAND Study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is recently weathered from Granite or Gneiss quartz crystals will be angular. It is called ''sharp sand'' in the building trade where it is preferred for concrete, and in gardening where it is used as a soil amendment to loosen clay soils. Sand that is transported long distances by water or wind will be rounded, with characteristic abrasion patterns on the grain surface. Desert sand is typically rounded. People who collect sand as a hobby are known as Arenophile s or psammofiles. USES OF SAND (DB class 403) releases sand from several bogies to the rails.]]
HAZARDS about to bury itself in sand]] While sand is generally harmless, one must take care with some activities involving sand such as Sandblasting . Bags of silica sand used for sandblasting now carry labels warning the user to wear respiratory protection and avoid breathing the fine silica dust. There have been a number of lawsuits in recent years where workers have developed Silicosis , a Lung Disease caused by inhalation of fine silica particles over long periods of time. Material Safety Data Sheet s (MSDS) for silica sand state that "excessive inhalation of crystalline silica is a serious health concern". {Link without Title} In areas of high Pore Water Pressure sand can partially liquefy to form Quicksand . Quicksand, once dried, produces a considerable barrier to escape for creatures caught within, who often die from exposure as a result. SEE ALSO
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