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{{Short description|Granular material composed of finely divided rock and mineral particles}}
{{Other uses}}
{{pp|small=yes}}
{{Use dmy dates|date=October 2019}}
[[File:Libya 4608 Idehan Ubari Dunes Luca Galuzzi 2007.jpg|upright=1.35|thumb|Sand [[dune]]s in the [[Idehan Ubari]], Libya]]
[[File:00065 sand collage.jpg|thumb|Depiction of sands:<br> glass, dune, quartz,<br> volcanic, biogenic coral, pink coral,<br>volcanic, garnet, olivine.<br>Samples are from the [[Gobi Desert]], [[Estonia]], [[Hawaii]] and the mainland United States. (1×1 cm each)<ref name="sand-collage">{{cite web|url=http://www.sandatlas.org/sand-types/|title=Sand types|author=Siim Sepp|publisher=sandatlas.org|access-date=17 February 2020|archive-url=https://web.archive.org/web/20190813235728/http://www.sandatlas.org/sand-types/|archive-date=13 August 2019|url-status=live}}</ref>]]
'''Sand''' is a [[granular material]] composed of finely divided [[mineral]] particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than [[gravel]] and coarser than [[silt]]. Sand can also refer to a [[soil texture|textural class]] of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass.<ref>{{cite book|title=Glossary of terms in soil science.|date=1976|publisher=Agriculture Canada|location=Ottawa|isbn=978-0662015338|page=35|url=http://sis.agr.gc.ca/cansis/publications/manuals/1976-glossary/pub1459_report.pdf|access-date=11 August 2014|archive-date=14 February 2019|archive-url=https://web.archive.org/web/20190214063705/http://sis.agr.gc.ca/cansis/publications/manuals/1976-glossary/pub1459_report.pdf|url-status=live}}</ref>
The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland [[continent]]al settings and non-[[tropical]] coastal settings is [[silica]] (silicon dioxide, or SiO<sub>2</sub>), usually in the form of [[quartz]].
[[Calcium carbonate]] is the second most common type of sand. One such example of this is [[aragonite]], which has been created over the past 500{{nbsp}}million years by various forms of life, such as [[coral]] and [[shellfish]]. It is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years, as in the [[Caribbean]]. Somewhat more rarely, sand may be composed of [[calcium sulfate]], such as [[gypsum]] and [[Selenite (mineral)|selenite]], as is found in places such as [[White Sands National Park]] and [[Salt Plains National Wildlife Refuge]] in the U.S.
Sand is a [[non-renewable resource]] over human timescales, and sand suitable for making [[concrete]] is in high demand.<ref>{{cite news|last1=Constable|first1=Harriet|title=How the demand for sand is killing rivers|url=https://www.bbc.com/news/magazine-41123284|access-date=9 September 2017|work=BBC News Magazine|date=3 September 2017|archive-date=3 September 2017|archive-url=https://web.archive.org/web/20170903103838/https://www.bbc.com/news/magazine-41123284|url-status=live}}</ref> Desert sand, although plentiful, is not suitable for concrete. Fifty billion tons of beach sand and fossil sand are used each year for construction.<ref>{{cite news |last=Albarazi |first=Hannah |title=The Slippery Slopes of the World Sand Shortage |url=https://www.overtureglobal.io/story/the-slippery-slopes-of-the-world-sand-shortage |access-date=29 March 2019 |archive-date=29 March 2019 |archive-url=https://web.archive.org/web/20190329221004/https://www.overtureglobal.io/story/the-slippery-slopes-of-the-world-sand-shortage |url-status=live }}</ref>
==Composition==
[[File:HeavyMineralsBeachSand.jpg|thumb|Heavy minerals (dark) in a quartz beach sand ([[Chennai]], India)]]
[[File:CoralPinkSandDunesSand.JPG|thumb|Sand from [[Coral Pink Sand Dunes State Park]], [[Utah]]. These are grains of [[quartz]] with a [[hematite]] coating providing the orange color.]]
[[File:PismoBeachSand.JPG|thumb|Sand from [[Pismo Beach, California]]. Components are primarily [[quartz]], [[chert]], [[igneous rock]], and shell fragments.]]
The exact definition of sand varies. The scientific [[Unified Soil Classification System]] used in engineering and geology corresponds to US Standard Sieves, and defines sand as particles with a diameter of between 0.074 and 4.75 millimeters.<ref>[ftp://ftp.fao.org/fi/cdrom/fao_training/fao_training/general/x6706e/x6706e11.htm Unified Soil Classification System]{{Dead link|date=May 2019 |bot=InternetArchiveBot |fix-attempted=yes}}</ref> By another definition, in terms of [[grain size|particle size]] as used by [[geologist]]s, sand particles range in diameter from 0.0625&nbsp;mm (or {{frac|1|16}}&nbsp;mm) a volume of approximately 0.00012 cubic millimetres, to 2&nbsp;mm, a volume of approximately 4.2 cubic millimetres, the difference in volumes being 34,688 measures difference.<ref>{{cite book|last1=Pettijohn|first1=FJ|last2=Potter|first2=PE|last3=Siever|first3=Raymond|title=Sand and Sandstone|url=https://books.google.com/books?id=FFEyBwAAQBAJ&dq=sand&pg=PA7|date=1972|publisher=[[Springer Verlag]]|location=New York|isbn=9780387900711|page=1|access-date=9 March 2021|archive-date=2 July 2021|archive-url=https://web.archive.org/web/20210702100242/https://www.google.co.uk/books/edition/Sand_and_Sandstone/FFEyBwAAQBAJ?hl=en&gbpv=1&dq=sand&pg=PA7&printsec=frontcover|url-status=live}}</ref> Any particle falling within this range of sizes is termed a ''sand grain''. Sand grains are between [[gravel]] (with particles ranging from 2&nbsp;mm up to 64&nbsp;mm by the latter system, and from 4.75&nbsp;mm up to 75&nbsp;mm in the former) and [[silt]] (particles smaller than 0.0625&nbsp;mm down to 0.004&nbsp;mm). The size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02&nbsp;mm were considered sand under the [[Albert Atterberg]] standard in use during the early 20th century. The grains of sand in [[Archimedes]]' ''[[The Sand Reckoner]]'' written around 240 BCE, were 0.02&nbsp;mm in diameter. A 1938 specification of the [[United States Department of Agriculture]] was 0.05&nbsp;mm.<ref>Urquhart, Leonard Church, "Civil Engineering Handbook" McGraw-Hill Book Company (1959) p. 8-2</ref> A 1953 engineering standard published by the [[American Association of State Highway and Transportation Officials]] set the minimum sand size at 0.074&nbsp;mm. Sand feels gritty when rubbed between the fingers. [[Silt]], by comparison, feels like [[flour]].
[[International Organization for Standardization|ISO]] 14688 grades sands as fine, medium, and coarse with ranges 0.063&nbsp;mm to 0.2&nbsp;mm to 0.63&nbsp;mm to 2.0&nbsp;mm. In the United States, sand is commonly divided into five sub-categories based on size: very fine sand ({{frac|1|16}} – {{frac|1|8}}&nbsp;mm diameter), fine sand ({{frac|1|8}}&nbsp;mm – {{frac|1|4}}&nbsp;mm), medium sand ({{frac|1|4}}&nbsp;mm – {{frac|1|2}}&nbsp;mm), coarse sand ({{frac|1|2}}&nbsp;mm – 1&nbsp;mm), and very coarse sand (1&nbsp;mm – 2&nbsp;mm). These sizes are based on the [[grain size|Krumbein phi scale]], where size is Φ = -log<sub>2</sub>D; D being the particle 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.
[[File:Volcanic sand (Perissa, Santorini, Greece).jpg|thumb|Close up of black volcanic sand from Perissa, [[Santorini]], Greece]]
The most common constituent of sand, in inland continental settings and non-tropical coastal settings, is [[silica]] (silicon dioxide, or SiO<sub>2</sub>), usually in the form of [[quartz]], which, because of its chemical inertness and considerable hardness, is the most common [[mineral]] resistant to [[weathering]].
The composition of mineral sand is highly variable, depending on the local rock sources and conditions. The bright [[coral sand|white sands]] found in tropical and subtropical coastal settings are eroded [[limestone]] and may contain [[coral]] and [[seashell|shell]] fragments in addition to other [[organism|organic]] or organically derived fragmental material, suggesting that sand formation depends on living organisms, too.<ref>[http://www.susanscott.net/Oceanwatch2002/mar1-02.html Seaweed also plays a role in the formation of sand] {{Webarchive|url=https://web.archive.org/web/20170701012717/http://www.susanscott.net/Oceanwatch2002/mar1-02.html |date=1 July 2017 }}. Susanscott.net (1 March 2002). Retrieved on 24 November 2011.</ref> The [[gypsum]] sand dunes of the [[White Sands National Park]] in [[New Mexico]] are famous for their bright, white color. [[Arkose]] is a sand or [[sandstone]] with considerable [[feldspar]] content, derived from [[weathering]] and [[erosion]] of a (usually nearby) [[granite|granitic]] rock outcrop. Some sands contain [[magnetite]], [[chlorite group|chlorite]], [[glauconite]], or [[gypsum]]. Sands rich in [[magnetite]] are dark to black in color, as are sands derived from volcanic [[basalt]]s and [[obsidian]]. [[Chlorite group|Chlorite]]-[[glauconite]] bearing sands are typically green in color, as are sands derived from [[basaltic]] [[lava]] with a high [[olivine]] content. Many sands, especially those found extensively in [[Southern Europe]], have [[iron]] impurities within the quartz [[crystal]]s of the sand, giving a deep yellow color. Sand deposits in some areas contain [[garnet]]s and other resistant minerals, including some small [[gemstone]]s.
==Sources==
Rocks [[erosion|erode]] or [[weathering|weather]] over a long period of time, mainly by water and wind, and their [[sediment]]s are transported downstream. These sediments continue to break apart into smaller pieces until they become fine grains of sand. The type of rock the sediment originated from and the intensity of the environment give different compositions of sand. The most common rock to form sand is [[granite]], where the [[feldspar]] minerals dissolve faster than the [[quartz]], causing the rock to break apart into small pieces. In high energy environments rocks break apart much faster than in more calm settings. In granite rocks this results in more feldspar minerals in the sand because they do not have as much time to dissolve away. The term for sand formed by weathering is "epiclastic."<ref>{{cite book |title=Sand|last=Gilman|first=Larry|publisher=The Gale Encyclopedia of Science |year=2014|edition=5|volume=7|pages=3823–3824}}</ref>
Sand from rivers are collected either from the river itself or its [[floodplain|flood plain]] and accounts for the majority of the sand used in the construction industry. Because of this, many small rivers have been depleted, causing environmental concern and economic losses to adjacent land. The rate of sand mining in such areas greatly outweighs the rate the sand can replenish, making it a non-renewable resource.<ref name=":0">{{cite book|title=Sand Mining|last=Padmalal|first=Maya|publisher=Springer, Dordrecht|year=2014|isbn=978-94-017-9143-4|pages=155–160|chapter=Sources of Sand and Conservation}}</ref>
Sand dunes are a consequence of dry conditions or wind deposition. The [[Sahara|Sahara Desert]] is very dry because of its geographic location and proximity to the [[equator]]. It is known for its vast sand dunes, which exist mainly due to a lack of vegetation and water. Over time, wind blows away fine particles, such as clay and dead organic matter, leaving only sand and larger rocks. Only 15% of the Sahara is sand dunes, while 70% is bare rock.<ref>{{cite book|chapter-url=https://www.encyclopedia.com/places/africa/african-physical-geography/sahara|title=The Columbia Encyclopedia|publisher=Columbia University Press|year=2000|isbn=9780787650155|edition=6|chapter=Sahara|url-access=registration|url=https://archive.org/details/columbiaencyclop00laga}}</ref> The wind is responsible for creating these different environments and shaping the sand to be round and smooth. These properties make desert sand unusable for construction.<ref>{{cite news|url=https://www.thehindu.com/sci-tech/energy-and-environment/what-is-the-reason-for-not-using-sea-and-desert-sand-for-construction/article7489192.ece|title=What is the reason for not using sea and desert sand for construction?|date=2 August 2015|work=The Hindu|language=en-IN|issn=0971-751X|access-date=9 April 2019|archive-date=15 December 2019|archive-url=https://web.archive.org/web/20191215054245/https://www.thehindu.com/sci-tech/energy-and-environment/what-is-the-reason-for-not-using-sea-and-desert-sand-for-construction/article7489192.ece|url-status=live}}</ref>
Beach sand is also formed by erosion. Over thousands of years, rocks are eroded near the shoreline from the constant motion of waves and the sediments build up. Weathering and river deposition also accelerate the process of creating a beach, along with marine animals interacting with rocks, such as eating the algae off of them. Once there is a sufficient amount of sand, the beach acts as a barrier to keep the land from eroding any further. This sand is ideal for construction as it is angular and of various sizes.<ref>{{cite web|url=https://www.worldatlas.com/articles/how-is-a-beach-formed.html|title=How Is A Beach Formed?|website=WorldAtlas|date=19 December 2017|language=en|access-date=10 April 2019|archive-date=13 December 2019|archive-url=https://web.archive.org/web/20191213232435/https://www.worldatlas.com/articles/how-is-a-beach-formed.html|url-status=live}}</ref>
Marine sand (or ocean sand) comes from sediments transported into the ocean and the erosion of ocean rocks. The thickness of the sand layer varies, however it is common to have more sand closer to land; this type of sand is ideal for construction and is a very valuable commodity. Europe is the main miners of marine sand, which greatly hurts ecosystems and local fisheries.<ref name=":0" />
==Study==
[[File:Sand under electron microscope.jpg|thumb|[[Scanning electron micrograph]] showing grains of sand]]
[[File:Pitted sand grains Western Desert.jpg|thumb|Pitted sand grains from the [[Western Desert (Egypt)|Western Desert]], Egypt. Pitting is a consequence of wind transportation.]]
The study of individual grains can reveal much historical information as to the origin and kind of transport of the grain.<ref>Krinsley, D.H., Smalley, I.J. 1972. Sand. American Scientist 60, 286–291</ref> [[Quartz sand]] that is recently weathered from [[granite]] or [[gneiss]] quartz crystals will be angular. It is called [[grus (geology)|grus]] in geology or [[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. Organisms that thrive in sandy environments are psammophiles.<ref>{{cite dictionary|url=https://www.merriam-webster.com/dictionary/psammophile|title=Psammophile|dictionary=Merriam-Webster.com|access-date=27 January 2016|date=|archive-date=9 July 2017|archive-url=https://web.archive.org/web/20170709040138/https://www.merriam-webster.com/dictionary/psammophile|url-status=live}}</ref>
==Uses==
{{More citations needed section|date=January 2018}}
[[File:Песчинки-1. Желтый строительный песок.jpg|thumb|Sand grains of yellow building sand. Microscope Lumam P-8. EPI lighting. The photo of each grain of sand is the result of [[focus stacking|multifocal stacking]].]]
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* [[Abrasion (mechanical)|Abrasion]]: Before sandpaper, wet sand was used as an abrasive element between rotating devices with elastic surface and hard materials such as very hard stone (making of stone vases), or metal (removal of old stain before re-staining copper cooking pots).
* [[Agriculture]]: Sandy [[soil]]s are ideal for crops such as watermelons, peaches, and peanuts, and their excellent drainage characteristics make them suitable for intensive dairy farming.
* [[Air filtration]]: Finer sand particles mixed with cloth was commonly used in certain [[gas mask]] filter designs but have largely been replaced by [[microfiber]]s.
* [[Aquarium|Aquaria]]: Sand makes a low-cost aquarium base material which some believe is better than gravel for home use. It is also a necessity for saltwater [[reef tank]]s, which emulate environments composed largely of [[aragonite]] sand broken down from [[coral]] and [[shellfish]].
* [[Artificial reefs]]: [[Geotextile]] bagged sand can serve as the foundation for new reefs.
* [[Artificial island]]s in the [[Persian Gulf]].
* [[Beach nourishment]]: Governments move sand to [[beach]]es where tides, storms, or deliberate changes to the shoreline erode the original sand.<ref>{{cite web|url=https://www.npr.org/templates/story/story.php?storyId=12026379|title=Importing Sand, Glass May Help Restore Beaches|date=17 July 2007|work=NPR.org|access-date=4 April 2018|archive-date=2 July 2021|archive-url=https://web.archive.org/web/20210702100217/https://www.npr.org/templates/story/story.php?storyId=12026379|url-status=live}}</ref>
* [[Brick]]: Manufacturing plants add sand to a mixture of [[clay]] and other materials for manufacturing bricks.<ref>{{cite book|url=https://books.google.com/books?id=j3vJDAAAQBAJ&pg=PA80|title=Environmental and Engineering Geology -Volume III|last=Yong|first=Syed E. Hasan, Benedetto De Vivo, Bernhard Grasemann, Kurt Stüwe, Jan Lastovicka, Syed M. Hasan, Chen|date=5 December 2011|publisher=EOLSS Publications|isbn=978-1-84826-357-4|page=80|access-date=19 October 2019|archive-date=2 July 2021|archive-url=https://web.archive.org/web/20210702100218/https://books.google.com/books?id=j3vJDAAAQBAJ&pg=PA80|url-status=live}}</ref>
* [[cob (material)|Cob]]: Cob is a building material consisting of water, organic material (like straw), lime, and [[subsoil]], which largely consists of sand. Coarse sand makes up as much as 75% of cob.
* [[Concrete]]: Sand is often a principal component of this critical construction material.
* [[Glass]]: Sand rich in silica is the principal component in common glasses.
* [[Hydraulic fracturing]]: A drilling technique for natural gas, which uses rounded silica sand as a "[[Fracking proppants|proppant]]", a material to hold open cracks that are caused by the hydraulic fracturing process.
* Landscaping: Sand makes small hills and slopes (golf courses would be an example).
* [[Mortar (masonry)|Mortar]]: Sand is mixed with masonry cement or [[Portland cement]] and lime to be used in masonry construction.
* [[Paint]]: Mixing sand with paint produces a [[texture (crystalline)|textured finish]] for walls and ceilings or non-slip floor surfaces.
* Railroads: [[Railroad engineer|Engine drivers and rail transit operators]] use sand to improve the traction of wheels on the rails.
* Recreation: Playing with sand is a favorite beach activity. One of the most beloved uses of sand is to make sometimes intricate, sometimes simple structures known as [[sand castle]]s, proverbially impermanent. Special play areas for children, enclosing a significant area of sand and known as sandboxes, are common on many public playgrounds, and even at some single-family homes. Sand dunes are also popular among climbers, motorcyclists and [[beach buggy]] drivers.
* Roads: Sand improves traction (and thus traffic safety) in icy or snowy conditions.
* [[Sand animation]]: [[Performance art]]ists draw images in sand. Makers of animated films use the same term to describe their use of sand on frontlit or backlit glass.
* [[Sand casting]]: Casters moisten or oil [[molding sand]], also known as [[foundry]] sand and then shape it into molds into which they pour molten material. This type of sand must be able to withstand high temperatures and pressure, allow gases to escape, have a uniform, small grain size, and be non-reactive with metals.
* [[Sandbag]]s: These protect against floods and gunfire. The inexpensive bags are easy to transport when empty, and unskilled volunteers can quickly fill them with local sand in emergencies.
* [[Sandblasting]]: Graded sand serves as an [[abrasive]] in cleaning, preparing, and polishing.
* [[Silicon]]: Quartz sand is a raw material for [[Silicon#Production|the production of silicon]].
* [[Early thermal weapons#Water, sand and other heated missiles|Thermal weapon]]: While not in widespread use anymore, sand used to be heated and poured on invading troops in the classical and medieval time periods.
* [[Water filtration]]: [[Media filter]]s use sand for filtering water. It is also commonly used by many water treatment facilities, often in the form of [[rapid sand filter]]s.
* [[Tayammum]]: Tayammum is an [[Islam]]ic ritual wiping of parts of the body.
* [[Zoanthid]] "skeletons": Animals in this order of marine [[benthic]] [[cnidaria]]ns related to [[coral]]s and [[sea anemone]]s incorporate sand into their [[mesoglea]] for structural strength, which they need because they lack a true skeleton.
==Resources and environmental concerns==
Only some sands are suitable for the construction industry, for example for making [[concrete]]. Grains of desert sand are rounded by being blown in the wind, and for this reason do not produce solid concrete, unlike the rough sand from the sea. Because of the growth of population and of cities and the consequent construction activity there is a huge demand for these special kinds of sand, and natural sources are running low. In 2012 French director [[Denis Delestrac]] made a documentary called "[[Sand Wars]]" about the impact of the lack of construction sand. It shows the ecological and economic effects of both legal and illegal trade in construction sand.<ref>{{Cite web|title=SAND WARS|url=http://www.sand-wars.com/|access-date=2023-02-23|website=www.sand-wars.com}}</ref><ref>{{cite journal|title=The story of climate change gets star treatment|journal=[[New Scientist]]|date=26 April 2014|pages=28–9|url=https://www.newscientist.com/article/dn25433-the-story-of-climate-change-gets-star-treatment/|author=Simon Ings|author-link=Simon Ings|access-date=29 May 2019|archive-date=4 November 2014|archive-url=https://web.archive.org/web/20141104184048/http://www.newscientist.com/article/mg22229660.800?full=true|url-status=live}}</ref><ref>[http://future.arte.tv/de/thema/straende-gefahr#article-anchor-1781 Strände in Gefahr?] {{Webarchive|url=https://web.archive.org/web/20150924012321/http://future.arte.tv/de/thema/straende-gefahr#article-anchor-1781 |date=24 September 2015 }} Arte Future, last updated 23 April 2014</ref>
To retrieve the sand, the method of hydraulic dredging is used. This works by pumping the top few meters of sand out of the water and filling it into a boat, which is then transported back to land for processing. All [[marine life]] mixed in with the extracted sand is killed and the ecosystem can continue to suffer for years after the mining is complete. Not only does this affect marine life, but also the local fishing industries because of the loss of life, and communities living close to the water's edge. When sand is taken out of the water it increases the risk of landslides, which can lead to loss of agricultural land and/or damage to dwellings.<ref>{{cite journal|last=Kim|first=Tae Goun |date=14 September 2007|title=The economic costs to fisheries because of marine sand mining in Ongjin Korea: Concepts, methods, and illustrative results|journal=Ecological Economics|volume=65|issue=3|pages=498–507 |doi=10.1016/j.ecolecon.2007.07.016}}</ref>
Sand's many uses require a significant [[dredging]] industry, raising environmental concerns over fish depletion, landslides, and flooding.<ref>{{cite news|last1=Torres|first1=Aurora|display-authors=etal|title=The world is facing a global sand crisis|url=https://theconversation.com/the-world-is-facing-a-global-sand-crisis-83557|access-date=9 September 2017|work=The Conversation|date=8 September 2017|archive-date=9 July 2018|archive-url=https://web.archive.org/web/20180709131826/https://theconversation.com/the-world-is-facing-a-global-sand-crisis-83557|url-status=live}}</ref> Countries such as China, Indonesia, Malaysia, and Cambodia ban sand exports, citing these issues as a major factor.<ref>{{cite news|url=https://www.economist.com/asia/2009/10/08/the-hourglass-effect|title=The hourglass effect|date=8 October 2009|access-date=14 October 2009|newspaper=The Economist|archive-date=16 December 2018|archive-url=https://web.archive.org/web/20181216115301/https://www.economist.com/asia/2009/10/08/the-hourglass-effect|url-status=live}}</ref> It is estimated that the annual consumption of sand and gravel is 40 billion tons and sand is a US$70 billion global industry.<ref>{{cite magazine|last1=Beiser|first1=Vince|title=The Deadly Global War for Sand|url=https://www.wired.com/2015/03/illegal-sand-mining/|access-date=26 March 2015|magazine=Wired|date=26 March 2015|archive-date=16 April 2018|archive-url=https://web.archive.org/web/20180416183348/https://www.wired.com/2015/03/illegal-sand-mining/|url-status=live}}</ref> With increasing use, more is expected to come from recycling and alternatives to sand.<ref name="Torres">{{cite journal |last1=Torres |first1=Aurora |last2=Simoni |first2=Mark U. |last3=Keiding |first3=Jakob K. |last4=Müller |first4=Daniel B. |last5=zu Ermgassen |first5=Sophus O.S.E. |author6-link=Jianguo Liu |last6=Liu |first6=Jianguo |last7=Jaeger |first7=Jochen A.G. |last8=Winter |first8=Marten |last9=Lambin |first9=Eric F. |title=Sustainability of the global sand system in the Anthropocene |journal=One Earth |date=May 2021 |volume=4 |issue=5 |pages=639–650 |doi=10.1016/j.oneear.2021.04.011|bibcode=2021OEart...4..639T |doi-access=free }}</ref>
The global demand for sand in 2017 was 9.55 billion tons as part of a $99.5 billion industry.<ref>{{cite web|url=https://www.reuters.com/article/us-climatechange-greenland/as-ice-melts-greenland-could-become-big-sand-exporter-study-idUSKCN1Q01YG|title=As ice melts, Greenland could become big sand exporter: study|work=reuters.com|first=Alister|last=Doyle|date=11 February 2019|access-date=12 February 2019|archive-date=7 August 2020|archive-url=https://web.archive.org/web/20200807022626/https://www.reuters.com/article/us-climatechange-greenland/as-ice-melts-greenland-could-become-big-sand-exporter-study-idUSKCN1Q01YG|url-status=live}}</ref> In April 2022, the [[United Nations Environment Programme]] (UNEP) published a report stating that 50 billion tons of sand and gravel were being used every year. The report made 10 recommendations, including a ban on beach extraction, to avert a crisis, and move toward a [[circular economy]] for the two resources.<ref name="unep 2022-04-28">{{cite press release |author=<!--Not stated--> |title=Our use of sand brings us "up against the wall", says UNEP report |url=https://www.unep.org/news-and-stories/press-release/our-use-sand-brings-us-against-wall-says-unep-report |location=Geneva |publisher=[[United Nations Environment Programme]] (UNEP) |date=2022-04-26 |access-date=2022-04-28}}</ref><ref name="abc 2022-04-28">{{cite news |title=The world is using sand faster than it can be replaced |url=https://www.abc.net.au/news/2022-04-28/un-warns-of-looming-sand-crisis-as-population-cities-grow/101021160#:~:text=A%20United%20Nations%20report%20calls,amid%20population%20growth%20and%20urbanisation. |access-date=28 April 2022 |work=[[ABC News (Australia)|ABC News]] |agency=[[Reuters]] |date=28 April 2022 |language=en-AU}}</ref>
==Hazards==
While sand is generally non-toxic, sand-using activities such as [[sandblasting]] require precautions. Bags of silica sand used for sandblasting now carry labels warning the user to wear respiratory protection to avoid breathing the resulting fine silica [[dust]]. [[Safety data sheet]]s for silica sand state that "excessive inhalation of crystalline silica is a serious health concern."<ref>[http://www.simplot.com/industrial/silica/silica_msds.cfm Silica sand MSDS] {{webarchive|url=https://web.archive.org/web/20060311043051/http://www.simplot.com/industrial/silica/silica_msds.cfm |date=11 March 2006}}. Simplot (13 March 2011). Retrieved on 24 November 2011.</ref>
In areas of high [[pore water pressure]], sand and salt water can form [[quicksand]], which is a [[colloid]] [[hydrogel]] that behaves like a liquid. Quicksand produces a considerable barrier to escape for creatures caught within, who often die from exposure (not from submersion) as a result.
People sometimes dig holes in the sand at beaches for recreational purposes, but if too deep they can result in serious injury or death in the event of a collapse.<ref>{{Cite web|last1=Ellement|first1=John R.|last2=Yan|first2=Matt|last3=Annear|first3=Steve |date=May 18, 2022 |title=Maine man, 18, killed in sand collapse on New Jersey beach; dad recalls his 'quirky' personality |url=https://www.bostonglobe.com/2022/05/18/metro/maine-man-18-killed-sister-hurt-when-hole-collapses-new-jersey-beach/|access-date=2023-02-23|website=BostonGlobe.com|language=en-US}}</ref>
==Manufacture==
Manufactured sand (M sand) is sand made from rock by artificial processes, usually for construction purposes in cement or concrete. It differs from river sand by being more angular, and has somewhat different properties.<ref>{{cite journal |pmc= 5456819|year= 2016|last1= Pilegis|first1= M.|title= An Investigation into the Use of Manufactured Sand as a 100% Replacement for Fine Aggregate in Concrete|journal= Materials|volume= 9|issue= 6|pages= 440|last2= Gardner|first2= D.|last3= Lark|first3= R.|pmid= 28773560|doi= 10.3390/ma9060440|bibcode= 2016Mate....9..440P|doi-access= free}}</ref>
==Case studies==
In [[Dubai]], [[United Arab Emirates]], sand needed to construct infrastructure and create the [[Dubai Islands]] exceeds local supplies, requiring sand from [[Australia]]. The artificial islands required more than 835 million tonnes of sand, at a cost greater than $26 billion USD.<ref>{{cite journal|last=Peduzzi|first=Pascal|date=April 2014|title=Sand, rarer than one thinks|url=https://archive-ouverte.unige.ch/unige:75919|journal=Environmental Development|volume=11|pages=208–218|doi=10.1016/j.envdev.2014.04.001|access-date=29 May 2019|archive-date=29 May 2019|archive-url=https://web.archive.org/web/20190529230621/https://archive-ouverte.unige.ch/unige:75919|url-status=live}}</ref>
==See also==
{{Portal-inline|Earth Sciences}}
<!-- Please respect alphabetical order -->
{{Div col|colwidth=20em|small=no}}
* {{annotated link|Aggregate (geology)}}
* {{annotated link|Beach}}
* {{annotated link|Construction aggregate}}
* {{annotated link|Coral Pink Sand Dunes State Park}}
* {{annotated link|Desert sand (color)}}
* {{annotated link|Dry quicksand}}
* {{annotated link|Energetically modified cement}} (EMC)
* {{annotated link|Heavy mineral sands ore deposits}}
* {{annotated link|Oil sands}}
* {{annotated link|Papakolea Beach}}
* {{annotated link|Particle size}}
* {{annotated link|Punaluʻu Beach}}
* {{annotated link|Quicksand}}
* {{annotated link|Red Sand Beach}}
* {{annotated link|Revolving rivers}}
* {{annotated link|Sand art and play}}
* {{annotated link|Sand Beach (disambiguation)}}
* [[Sand equivalent test]]
* {{annotated link|Sand island}}
* {{annotated link|Sand mining}}
* {{annotated link|Psammomys|Sand rat}}
* {{annotated link|Sandstone}}
* {{annotated link|Dust storm|Sandstorm}}
* {{annotated link|Sand theft}}
* {{annotated link|Singing sand}}
* {{annotated link|White Sands National Park}}
{{Div col end}}
==References==
{{Reflist|30em}}
==Further reading==
* {{cite book |title=The World in a Grain: The Story of Sand and How It Transformed Civilization |year=2018 |author=Vince Beiser |publisher=Riverhead Books |isbn=978-0399576423}}
==External links==
{{Wiktionary}}
{{Wikiquote}}
{{Commons category}}
* [https://web.archive.org/web/20091201183346/http://www.beaufortcountylibrary.org/htdocs-sirsi/beachsan.htm ''Beach Sand: What It Is, Where It Comes From and How It Gets Here''] - Beaufort County Library
* {{cite NSRW|wstitle=Sand}}
;Sand mining side-effects
* [https://www.newyorker.com/magazine/2017/05/29/the-world-is-running-out-of-sand The World Is Running Out Of Sand] - ''New York Times''
* [https://www.nytimes.com/2017/03/01/magazine/sand-mining-india-how-to-steal-a-river.html Sand Mining In India Rivers Causing Problems] - ''New York Times''
* [https://www.bbc.com/news/magazine-41123284 How Demand For Sand Is Killing Rivers In Africa] - BBC
* [http://www.bbc.com/capital/story/20160502-even-desert-city-dubai-imports-its-sand-this-is-why Dubai Imports Sand] - BBC
* [https://www.reuters.com/business/environment/sand-crisis-looms-world-population-surges-un-warns-2022-04-26/ Sand crisis looms as world population surges, U.N. warns] - Reuters
{{Geotechnical engineering|state=collapsed}}
{{Coastal geography}}
{{Authority control}}
[[Category:Sand| ]]
[[Category:Soil-based building materials]]