Editing Limestone (section)

== Uses ==
{{See also|ashlar}}
[[File:Malta - Qrendi - Hagar Qim and Mnajdra Archaeological Park - Hagar Qim 08 ies.jpg|thumb|The [[Megalithic Temples of Malta]] such as [[Ħaġar Qim]] are built entirely of limestone. They are among the oldest freestanding structures in existence.<ref name=cassar>{{cite book |last= Cassar |first= Joann |year=2010 |contribution= The use of limestone in historic context |editor-last= Smith |editor-first= Bernard J. |title= Limestone in the Built Environment: Present-day Challenges for the Preservation of the Past |publisher= Geographical Society of London |pages= 13–23 |isbn=978-1-86239-294-6 |url=https://books.google.com/books?id=wXCoMb3CU4YC&pg=PA17 |access-date= 20 December 2024}}</ref>]]
[[File:Gizeh Cheops BW 1.jpg|thumb|The [[Great Pyramid of Giza]], one of the [[Seven Wonders of the Ancient World]], had an outside cover made entirely from limestone.]]

Limestone is a raw material that is used globally in a variety of different ways including construction, agriculture and as industrial materials.<ref name="Oates-2008" /> Limestone is very common in architecture, especially in Europe and North America. Many landmarks across the world, including the [[Great Pyramid of Giza|Great Pyramid]] and its associated [[Giza pyramid complex|complex]] in [[Giza, Egypt]], were made of limestone. So many buildings in [[Kingston, Ontario]], Canada were, and continue to be, constructed from it that it is nicknamed the 'Limestone City'.<ref>{{cite web |url= http://www.citylifeontario.com/kingston/ |title= Welcome to the Limestone City |access-date=13 February 2008 |url-status= live |archive-url= https://web.archive.org/web/20080220171909/http://www.citylifeontario.com/kingston/ |archive-date= 20 February 2008 }}</ref> Limestone, metamorphosed by heat and pressure produces marble, which has been used for many statues, buildings and stone tabletops.<ref name="Corathers-2019" /> On the island of [[Malta]], a variety of limestone called [[Globigerina Limestone Formation|Globigerina limestone]] was, for a long time, the only building material available, and is still very frequently used on all types of buildings and sculptures.<ref>{{cite journal |last1=Cassar |first1=Joann |title=The use of limestone in a historic context – the experience of Malta |journal=Geological Society, London, Special Publications |date=2010 |volume=331 |issue=1 |pages=13–25 |doi=10.1144/SP331.2|bibcode=2010GSLSP.331...13C |s2cid=129082854 }}</ref>

Limestone can be processed into many various forms such as brick, cement, powdered/crushed, or as a filler.<ref name="Oates-2008">{{Cite book |last=Oates |first=J. A. H. |url=https://books.google.com/books?id=MVoEMNI5Vb0C |title=Lime and Limestone: Chemistry and Technology, Production and Uses |date=2008-07-11 |publisher=John Wiley & Sons |isbn=978-3-527-61201-7 |pages=64 |language=en |chapter=7.2 Market Overview}}</ref> Limestone is readily available and relatively easy to cut into blocks or more elaborate carving.<ref name="cassar" /> Ancient American sculptors valued limestone because it was easy to work and good for fine detail. Going back to the Late Preclassic period (by 200–100 BCE), the [[Maya civilization]] (Ancient Mexico) created refined sculpture using limestone because of these excellent carving properties. The Maya would decorate the ceilings of their sacred buildings (known as [[Ancient Maya art|lintels]]) and cover the walls with carved limestone panels. Carved on these sculptures were political and social stories, and this helped communicate messages of the king to his people.<ref>{{cite book|first1=Linda |last1=Schele |first2=Mary Ellen |last2=Miller |title=The Blood of Kings: Dynasty and Ritual in Maya Art |publisher=Kimbell Art Museum |page=41}}</ref> Limestone is long-lasting and stands up well to exposure, which explains why many limestone ruins survive. However, it is very heavy ([[density]] 2.6<ref name="Sharma1997">{{citation|author1=P. V. Sharma|title=Environmental and Engineering Geophysics|year=1997|publisher=Cambridge University Press|isbn= 1-139-17116-X|page=17|doi=10.1017/CBO9781139171168}}</ref>), making it impractical for tall buildings, and relatively expensive as a building material.

Limestone was most popular in the late 19th and early 20th centuries. Railway stations, banks and other structures from that era were made of limestone in some areas. It is used as a [[façade]] on some skyscrapers, but only in thin plates for covering, rather than solid blocks. In the United States, Indiana, most notably the [[Bloomington, Indiana|Bloomington]] area, has long been a source of high-quality quarried limestone, called [[Indiana limestone]]. Many famous buildings in London are built from [[Portland limestone]]. Houses built in [[Odesa]] in [[Ukraine]] in the 19th century were mostly constructed from limestone and the extensive remains of the mines now form the [[Odesa Catacombs]].<ref name="Odesa">{{cite web |url=https://leodessa.com/odessa-catacombs/ |title=Odessa catacombs |publisher=Odessa travel guide |access-date=13 June 2020}}</ref>

Limestone was also a very popular building block in the Middle Ages in the areas where it occurred, since it is hard, durable, and commonly occurs in easily accessible surface exposures. Many medieval churches and castles in Europe are made of limestone. [[Beer stone]] was a popular kind of limestone for medieval buildings in southern England.<ref name="ashurst">{{cite book|last1=Ashurst|first1=John|last2=Dimes|first2=Francis G.|title=Conservation of building and decorative stone|url=https://books.google.com/books?id=xPFx6bEPspgC&pg=PA117|year=1998|publisher=Butterworth-Heinemann|isbn=0-7506-3898-2|page=117}}</ref>

<gallery>
File:Limestone Mines at Cedar Creek.jpg|Limestone quarry at [[Cedar Creek (North Fork Shenandoah River)|Cedar Creek, Virginia]], US
File:Pargas Quarry-24.jpg|[[Nordkalk]]'s limestone quarry in [[Pargas]], [[Finland]]
File:Gozo, limestone quarry - cutting the stone.JPG|Cutting limestone blocks at a quarry in [[Gozo]], [[Malta]]
File:Kalkstein (nahe).JPG|Limestone as building material
File:Bermuda Number 178 limestone used as building material for walls.jpg|Limestone is used worldwide as building material.
</gallery>

Limestone is the raw material for production of lime, primarily known for treating soils, purifying water and [[smelting]] copper. Lime is an important ingredient used in chemical industries.<ref name="Bliss-2012-1">Bliss, J. D., Hayes, T. S., & Orris, G. J. (2012, August). Limestone—A Crucial and Versatile Industrial Mineral Commodity. Retrieved February 23, 2021, from https://pubs.usgs.gov/fs/2008/3089/fs2008-3089.pdf</ref> Limestone and (to a lesser extent) marble are reactive to acid solutions, making [[acid rain]] a significant problem to the preservation of artifacts made from this stone. Many limestone statues and building surfaces have suffered severe damage due to acid rain.<ref>{{cite journal|title=ICP on effects on materials |doi=10.1007/BF01186242 |volume=85 |issue=4 |journal=Water, Air, & Soil Pollution |pages=2701–2706|bibcode=1995WASP...85.2701R |last1=Reisener |first1=A. |last2=Stäckle |first2=B. |last3=Snethlage |first3=R. |year=1995 |s2cid=94721996 }}</ref><ref>{{cite web |url=http://www.iiasa.ac.at/Admin/PUB/Documents/WP-89-104.pdf |title=Approaches in modeling the impact of air pollution-induced material degradation |access-date=November 18, 2010 |archive-url=https://web.archive.org/web/20110716175635/http://www.iiasa.ac.at/Admin/PUB/Documents/WP-89-104.pdf |archive-date=July 16, 2011 |url-status=dead }}</ref> Likewise limestone gravel has been used to protect lakes vulnerable to acid rain, acting as a [[pH buffer]]ing agent.<ref>{{cite journal |last1=Clayton |first1=Janet L. |last2=Dannaway |first2=Eric S. |last3=Menendez |first3=Raymond |last4=Rauch |first4=Henry W. |last5=Renton |first5=John J. |last6=Sherlock |first6=Sean M. |last7=Zurbuch |first7=Peter E. |title=Application of Limestone to Restore Fish Communities in Acidified Streams |journal=North American Journal of Fisheries Management |date=1998 |volume=18 |issue=2 |pages=347–360 |doi=10.1577/1548-8675(1998)018<0347:AOLTRF>2.0.CO;2|bibcode=1998NAJFM..18..347C }}</ref> Acid-based cleaning chemicals can also etch limestone, which should only be cleaned with a neutral or mild [[alkali]]-based cleaner.<ref>{{cite web |last1=Hatch |first1=Jonathan |title=How to clean limestone |url=https://howtocleanthings.com/how-to-clean-limestone/ |website=How to Clean Things |publisher=Saint Paul Media, Inc. |access-date=5 February 2021 |date=18 April 2018}}</ref>

[[File:Litography press with map of Moosburg 01.jpg|thumb|A limestone plate with a negative map of [[Moosburg]] in Bavaria is prepared for a [[lithography]] print.]]
[[File:LIMEX limestone plastic, 2022 Japan 2.jpg|thumb|Plastic bag "made mainly from limestone"{{clarify|what does this actually mean?|date=April 2024}}]]

Other uses include:
* It is the raw material for the manufacture of [[quicklime]] (calcium oxide), [[slaked lime]] (calcium hydroxide), [[cement]] and [[mortar (masonry)|mortar]].{{sfn|Blatt|Middleton|Murray|1980|p=445}}
* Pulverized limestone is used as a soil conditioner to neutralize acidic soils ([[agricultural lime]]).<ref name="Oates2008">{{cite book|first=J. A. H.|last=Oates|title=Lime and Limestone: Chemistry and Technology, Production and Uses|url=https://books.google.com/books?id=MVoEMNI5Vb0C&pg=PA111|date=11 July 2008|publisher=[[John Wiley & Sons]]|isbn=978-3-527-61201-7|pages=111–3}}</ref>
* Is crushed for use as [[construction aggregate|aggregate]]—the solid base for many roads as well as in [[asphalt concrete]].{{sfn|Blatt|Middleton|Murray|1980|p=445}}
* As a [[reagent]] in [[flue-gas desulfurization]], where it reacts with [[sulfur dioxide]] for air pollution control.<ref>{{cite journal |last1=Gutiérrez Ortiz |first1=F. J. |last2=Vidal |first2=F. |last3=Ollero |first3=P. |last4=Salvador |first4=L. |last5=Cortés |first5=V. |last6=Giménez |first6=A. |title=Pilot-Plant Technical Assessment of Wet Flue Gas Desulfurization Using Limestone |journal=Industrial & Engineering Chemistry Research |date=February 2006 |volume=45 |issue=4 |pages=1466–1477 |doi=10.1021/ie051316o}}</ref>
* In [[glass making]], particularly in the manufacture of [[soda–lime glass]].<ref>{{Cite book|url=https://books.google.com/books?id=zNicdkuulE4C&q=Glass+making,+in+some+circumstances,+uses+limestone.&pg=PA1387|title=Industrial Minerals & Rocks: Commodities, Markets, and Uses|last=Kogel|first=Jessica Elzea|date=2006|publisher=SME|isbn=0-87335-233-5|language=en|url-status=live|archive-url=https://web.archive.org/web/20171216222141/https://books.google.com/books?id=zNicdkuulE4C&pg=PA1387&dq=Glass+making,+in+some+circumstances,+uses+limestone.&hl=en&sa=X&ved=0ahUKEwi65Iu0yI_YAhVT22MKHWTfAWgQ6AEIKTAA#v=onepage&q=Glass%20making,%20in%20some%20circumstances,%20uses%20limestone.&f=false|archive-date=16 December 2017}}</ref>
* As an additive toothpaste, paper, plastics, paint, tiles, and other materials as both white pigment and a cheap filler.<ref>{{cite book |last1=Huwald |first1=Eberhard |chapter=Calcium carbonate - pigment and filler |title=Calcium Carbonate | editor-first  = F. W. | editor-last = Tegethoff | publisher = Birkhäuser | location = Basel |date=2001 |pages=160–170 |doi=10.1007/978-3-0348-8245-3_7|isbn=3-0348-9490-2 }}</ref>
* As [[rock dust]], to suppress methane explosions in underground coal mines.<ref>{{cite journal |last1=Man |first1=C.K. |last2=Teacoach |first2=K.A. |year=2009 |title=How does limestone rock dust prevent coal dust explosions in coal mines? |journal=Mining Engineering |page=61 |url=https://www.cdc.gov/NIOSH/Mining/UserFiles/works/pdfs/hdlrdp.pdf |access-date=30 November 2020}}</ref>
* Purified, it is added to bread and cereals as a source of calcium.<ref>{{cite web |title=Why Fortified Flour? |url=https://www.wessexmill.co.uk/acatalog/Fortified-Flour.html |website=Wessex Mill |access-date=5 February 2021}}</ref>
* As a calcium supplement in livestock feed, such as for poultry (when ground up).<ref>{{cite news|url= http://poultryone.com/articles/calcium.html|title= A Guide to Giving Your Layer Hens Enough Calcium|work= Poultry One|url-status= live|archive-url= https://web.archive.org/web/20090403082817/http://poultryone.com/articles/calcium.html|archive-date= 3 April 2009}}</ref>
* For remineralizing and increasing the alkalinity of purified water to prevent pipe corrosion and to restore essential nutrient levels.<ref>{{cite web|url=https://www.who.int/water_sanitation_health/dwq/nutconsensus/en/|title= Nutrient minerals in drinking-water and the potential health consequences of consumption of demineralized and remineralized and altered mineral content drinking-water: Consensus of the meeting|work= World Health Organization report|url-status= dead|archive-url= https://web.archive.org/web/20071224165953/http://www.who.int/water_sanitation_health/dwq/nutconsensus/en/|archive-date= 24 December 2007}}</ref>
* In [[blast furnace]]s, limestone binds with silica and other impurities to remove them from the iron.<ref>{{cite book |last1=Tylecote |first1=R. F. |title=A history of metallurgy |date=1992 |publisher=Institute of Materials |location=London |isbn=0-901462-88-8 |edition=2nd}}</ref>
*It can aid in the removal of toxic components created from coal burning plants and layers of polluted molten metals.<ref name="Bliss-2012-1"/>

Many limestone [[Geological formation|formation]]s are porous and permeable, which makes them important [[petroleum reservoir]]s.<ref>{{cite journal |last1=Archie |first1=G.E. |title=Classification of Carbonate Reservoir Rocks and Petrophysical Considerations |journal=AAPG Bulletin |date=1952 |volume=36 |doi=10.1306/3D9343F7-16B1-11D7-8645000102C1865D}}</ref> About 20% of North American hydrocarbon reserves are found in carbonate rock. Carbonate reservoirs are very common in the petroleum-rich Middle East,{{sfn|Blatt|Middleton|Murray|1980|p=445}} and carbonate reservoirs hold about a third of all petroleum reserves worldwide.{{sfn|Boggs|2006|p=p=159}} Limestone formations are also common sources of metal ores, because their porosity and permeability, together with their chemical activity, promotes ore deposition in the limestone. The [[lead]]-[[zinc]] deposits of [[Missouri]] and the [[Northwest Territories]] are examples of ore deposits hosted in limestone.{{sfn|Blatt|Middleton|Murray|1980|p=445}}

=== Scarcity ===
Limestone is a major industrial raw material that is in constant demand. This raw material has been essential in the [[iron]] and [[steel]] industry since the nineteenth century.<ref name="Haumann-2020">{{cite journal | title=Critical and scarce: the remarkable career of limestone 1850–1914 | last=Haumann | first=S. | journal=European Review of History: Revue européenne d'histoire | year=2020 | volume=27 | issue=3 | pages=273–293 | doi=10.1080/13507486.2020.1737651| s2cid=221052279 }}</ref> Companies have never had a shortage of limestone; however, it has become a concern as the demand continues to increase<ref name="SparenbergHeymann">{{cite journal | title=Introduction: resource challenges and constructions of scarcity in the nineteenth and twentieth centuries | last1=Sparenberg | first1=O. | last2=Heymann | first2=M. | journal=European Review of History: Revue européenne d'histoire | year=2020 | volume=27 | issue=3 | pages=243–252 | doi=10.1080/13507486.2020.1737653| s2cid=221055042 | doi-access=free }}</ref> and it remains in high demand today.<ref name="ResearchAndMarkets">{{cite web | url=https://www.businesswire.com/news/home/20200609005311/en/Global-Limestone-Market-Analysis-and-Forecasts-2020-2027---Steady-Growth-Projected-over-the-Next-Few-Years---ResearchAndMarkets.com | title=Global Limestone Market Analysis and Forecasts 2020-2027 - Steady Growth Projected over the Next Few Years - ResearchAndMarkets.com | publisher=businesswire.com | work=Limestone - Global Market Trajectory & Analytics | date=9 June 2020 | access-date=24 March 2021 | author=ResearchAndMarkets.com}}</ref> The major potential threats to supply in the nineteenth century were regional availability and accessibility.<ref name="Haumann-2020" /> The two main accessibility issues were transportation and property rights. Other problems were high capital costs on plants and facilities due to environmental regulations and the requirement of zoning and mining permits.<ref name="Corathers-2019">{{cite book | url=https://books.google.com/books?id=arqJE6h4uJ4C&pg=SA43-PA1 | chapter=Lime | title=Metals and minerals: US Geological Survey Minerals Yearbook 2014, Volume 1 | publisher=[[USGS]] | last=Corathers | first=L.A. | date=15 February 2019 | page=43.1 | publication-date=2018 | publication-place=Washington, DC |isbn=978-1-4113-4253-8}}</ref> These two dominant factors led to the adaptation and selection of other materials that were created and formed to design alternatives for limestone that suited economic demands.<ref name="Haumann-2020" />

Limestone was classified as a critical raw material, and with the potential risk of shortages, it drove industries to find new alternative materials and technological systems. This allowed limestone to no longer be classified as critical as replacement substances increased in production; [[Minette (ore)|minette ore]] is a common substitute, for example.<ref name="Haumann-2020" />

=== Occupational safety and health ===
{{NFPA 704 | H= 1 | F= 0 | R= 0 | S= |caption=Limestone |ref=<ref name="MSDS"/>}}

Powdered limestone as a food additive is [[generally recognized as safe]]<ref>{{cite web |title=CFR - Code of Federal Regulations Title 21 |url=https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1409 |website=US Food & Drug Administration |publisher=US Department of Health & Human Services |access-date=5 February 2021}}</ref> and limestone is not regarded as a hazardous material. However, limestone dust can be a mild respiratory and skin irritant, and dust that gets into the eyes can cause [[corneal abrasion]]s. Because limestone contains small amounts of silica, inhalation of limestone dust could potentially lead to [[silicosis]] or [[cancer]].<ref name="MSDS">{{cite web |last1=Lhoist North America |title=Material Safety Data Sheet: Limestone |url=https://www.7springsfarm.com/content/MSDS_Limestone.pdf |access-date=5 February 2021}}</ref>

====United States====
The [[Occupational Safety and Health Administration]] (OSHA) has set the legal limit ([[permissible exposure limit]]) for limestone exposure in the workplace as {{cvt|15|mg/m3}} total exposure and {{cvt|5|mg/m3}} respiratory exposure over an 8-hour workday. The [[National Institute for Occupational Safety and Health]] (NIOSH) has set a [[recommended exposure limit]] (REL) of {{cvt|10|mg/m3}} total exposure and {{cvt|5|mg/m3}} respiratory exposure over an 8-hour workday.<ref>{{Cite web|website= NIOSH Pocket Guide to Chemical Hazards |title= Limestone|url = https://www.cdc.gov/niosh/npg/npgd0369.html|publisher= CDC|access-date =19 November 2015|url-status = live|archive-url = https://web.archive.org/web/20151120065513/http://www.cdc.gov/niosh/npg/npgd0369.html|archive-date = 20 November 2015}}</ref>

=== Graffiti ===
Removing [[graffiti]] from weathered limestone is difficult because it is a porous and permeable material. The surface is fragile, therefore usual abrasion methods run the risk of severe surface loss. Since it is an acid-sensitive stone, some cleaning agents cannot be used due to adverse effects.<ref>{{cite web |url=https://www.nps.gov/tps/how-to-preserve/briefs/38-remove-graffiti.htm |title=Removing Graffiti from Historic Masonry |first=Martin E. |last=Weaver |date=October 1995 |publisher=National Park Service |access-date=5 February 2019}}</ref>