Sand
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Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The composition of sand is highly variable, depending on the local rock sources and conditions, but 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. In terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm (or ⅟16 mm) to 2 mm. An individual particle in this range size is termed a sand grain. Sand grains are between gravel (with particles ranging from 2 mm up to 64 mm) and silt (particles smaller than 0.0625 mm down to 0.004 mm). The size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A 1938 specification of the United States Department of Agriculture was 0.05 mm. Sand feels gritty when rubbed between the fingers (silt, by comparison, feels like flour). ISO 14688 grades sands as fine, medium and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is commonly divided into five sub-categories based on size: very fine sand (⅟16 – ⅛ mm diameter), fine sand (⅛ mm – ¼ mm), medium sand (¼ mm – ½ mm), coarse sand (½ mm – 1 mm), and very coarse sand (1 mm – 2 mm). These sizes are based on the Krumbein phi scale, 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. From Wikipedia under the
GNU Free Documentation License NounDeclension of sand uncountable uncountable Common indefinite definite nominative sand sanden genitive sands sandenssand c.
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GNU Free Documentation License Matching Results for Sand:George SandTransl by Raphaël Ledos de Beaufort in Letters of George Sand Vol. III, p. 242. ... Gerard Hopkins) Lélia: The Life of George Sand (New York: Harper, 1954) p. 292. ... Neverwinter Nights 2 Sand: I think it is time everyone marched behind me, your new glorious leader. ... Sorry I pointed out the fact that you were a charlatan, Sand. ... Aldo Leopold 1.1 A Sand County Almanac, with essays on conservation from Round River (1966) ... A Sand County Almanac - with essays on conservation from Round River. ... From Wikiquote under the
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Recreation: Pets: Reptiles and Amphibians: Snakes ... This category contains information on the captive care and beeding of Eunectus murinus and notaeus the green and yellow Anacondas. Kids: School Time: Science: Living ... See also: Kids: School Time: Science: Living Things: Animals: Marine Life (45) Enchanted Learning: Sand Dollar [ ] - Features a print out and ...
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