Editing Niter

{{short description|Mineral form of potassium nitrate}}
{{redirect|Nitre|other uses|Nitre (disambiguation)}}
{{distinguish|Natron}}
{{Use American English|date=April 2021}}
{{Use mdy dates|date=April 2021}}
{{Infobox mineral
| name        = Niter
| category    = [[Nitrate]]s, [[oxide mineral]]
| boxwidth    =
| boxbgcolor  =
| image       = Niter from Tarapaca, Chile (cropped).jpg
| caption     = A piece of niter collected in Tarapaca, Chile
| formula     = KNO<sub>3</sub>
| IMAsymbol   = Nit<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| molweight   =
| strunz      = 5.NA.10
| dana        = 18.1.2.1
| system      = [[Orthorhombic crystal system|Orthorhombic]]
| class       = Dipyramidal (mmm) <br />[[H-M symbol]]: (2/m 2/m 2/m)
| symmetry    = ''C''mc2<sub>1</sub>
| color       = White
| habit       = [[Druse (geology)|Druse]] or [[acicular (crystal habit)|acicular]]
| cleavage    = Very good on {001}; good on {010}
| fracture    = Brittle
| mohs        = 2
| luster      = Vitreous
| refractive  = {{ubl
 | ''n''<sub>α</sub> = 1.332
 | ''n''<sub>β</sub> = 1.504
 | ''n''<sub>γ</sub> = 1.504
 }}
| opticalprop =
| birefringence =
| pleochroism =
| streak      = White
| gravity     = 2.10 (calc.)
| melt        =
| fusibility  =
| diagnostic  =
| solubility  = Soluble
| diaphaneity = Transparent
| other       =
| references  = <ref>{{Cite web|url=http://www.webmineral.com/data/Niter.shtml#.WhGUGEqnFPY.|title=Niter Mineral Data|website=www.webmineral.com}}</ref><ref>{{Cite web|url=https://www.mindat.org/show.php?id=2917|title=Niter: Mineral information, data and localities.|website=www.mindat.org}}</ref><ref>{{citation | last1 = Adiwidjaja | first1 = G. | last2 = Pohl | first2 = D. | year = 2003 | title = Superstructure of α-phase potassium nitrate | journal = Acta Crystallogr. C | volume = 59 | pages = 1139–40 | doi = 10.1107/S0108270103025277 | issue = 12| pmid = 14671340 | bibcode = 2003AcCrC..59I.139A }}.</ref>
}}

'''Niter''' or '''nitre'''<ref>{{cite web|title=Definition of nitre|url=http://www.merriam-webster.com/dictionary/nitre|publisher=[[Merriam-Webster]]|access-date=11 March 2016}}</ref> is the mineral form of [[potassium nitrate]], KNO<sub>3</sub>. It is a soft, white, highly soluble mineral found primarily in arid climates or cave deposits.

Potassium and other nitrates are of great importance for use in [[fertilizer]]s and, historically, [[gunpowder]]. Much of the world's demand is now met by synthetically produced nitrates, though the natural mineral is still mined and is still of significant commercial value.<ref>{{cite journal |last1=Barnum |first1=Dennis W. |title=Some History of Nitrates |journal=Journal of Chemical Education |date=December 2003 |volume=80 |issue=12 |pages=1393 |doi=10.1021/ed080p1393|bibcode=2003JChEd..80.1393B }}</ref><ref>{{cite journal |last1=Burkhardt |first1=John J. |last2=Heath |first2=Garvin A. |last3=Turchi |first3=Craig S. |title=Life Cycle Assessment of a Parabolic Trough Concentrating Solar Power Plant and the Impacts of Key Design Alternatives |journal=Environmental Science & Technology |date=15 March 2011 |volume=45 |issue=6 |pages=2457–2464 |doi=10.1021/es1033266|pmid=21391722 |bibcode=2011EnST...45.2457B |doi-access=free }}</ref>

Historically, the term ''niter'' was not well differentiated from [[natron]], both of which have been very vaguely defined but generally refer to compounds of [[sodium]] or [[potassium]] joined with [[carbonate]] or [[nitrate]] ions.

== Characteristics ==
Niter is a colorless to white mineral crystallizing in the [[orthorhombic]] [[crystal system]]. It is the mineral form of [[potassium nitrate]], {{chem2|KNO3}},<ref name=Jackson/> and is soft ([[Mohs hardness]] 2),<ref name="HoM"/> highly soluble in water,<ref name=Jackson>{{cite book |editor1-last=Jackson |editor1-first=Julia A. |title=Glossary of geology. |date=1997 |publisher=American Geological Institute |location=Alexandria, Virginia |isbn=0922152349 |edition=Fourth |chapter=niter}}</ref> and easily fusible. Its crystal structure resembles that of [[aragonite]], with potassium replacing calcium and nitrate replacing carbonate.<ref>{{cite book |last1=Klein |first1=Cornelis |last2=Hurlbut |first2=Cornelius S. Jr. |title=Manual of mineralogy : (after James D. Dana) |date=1993 |publisher=Wiley |location=New York |isbn=047157452X |edition=21st |page=418}}</ref> It occurs in the soils of arid regions and as massive encrustations and [[efflorescent]] growths on [[cave]]rn walls and ceilings where solutions containing [[alkali]] potassium and nitrate seep into the openings.<ref name=Jackson/> It occasionally occurs as prismatic [[Acicular (crystal habit)|acicular]] crystal groups, and individual crystals commonly show pseudohexagonal [[crystal twinning|twinning]] on [110]. Niter and other nitrates can also form in association with deposits of [[guano]] and similar organic materials.<ref name="HoM">{{cite web |last1=Anthony |first1=John W. |last2=Bideaux |first2=Richard A. |last3=Bladh |first3=Kenneth W. |last4=Nichols |first4=Monte C. |title=Niter |url=http://www.handbookofmineralogy.org/pdfs/niter.pdf |website=Handbook of Mineralogy |publisher=Mineral Data Publishing |access-date=28 December 2021 |date=2005}}</ref>

==History and etymology==
Niter as a term has been known since ancient times, although there is much historical confusion with [[natron]] (an impure sodium carbonate/bicarbonate), and not all of the ancient salts known by this name or similar names in the ancient world contained nitrate.<ref name=Jackson/> The name is from the [[Ancient Greek]] {{lang|grc|νιτρων}} {{lang|grc-Latn|nitron}} from [[Ancient Egyptian language|Ancient Egyptian]] {{lang|egy-Latn|netjeri}}, related to the [[Hebrew]] {{lang|he-Latn|néter}}, for salt-derived ashes (their interrelationship is not clear).<ref name="oed">{{oed|nitre}}</ref>

The Hebrew {{lang|he-Latn|néter}} may have been used as, or in conjunction, with [[soap]], as implied by [[Jeremiah]] 2:22, "For though thou wash thee with niter, and take thee much soap..." However, it is not certain which substance (or substances) the Biblical "neter" refers to, with some suggesting [[sodium carbonate]].<ref>{{cite journal |last1=Haberfield |first1=Paul |title=What's in a name: NaNO3 |journal=Journal of Chemical Education |date=January 1985 |volume=62 |issue=1 |pages=56 |doi=10.1021/ed062p56|bibcode=1985JChEd..62...56H }}</ref>

The [[Neo-Latin]] word for [[sodium]], {{lang|la|natrium}}, is derived from this same class of desert minerals called {{lang|fr|natron}} (French)<ref>{{oed|natrium}}</ref> through Spanish {{lang|es|natrón}} from Greek {{lang|grc|νίτρον}} ({{lang|grc-Latn|nitron}}), derived from Ancient Egyptian {{lang|egy-Latn|netjeri}}, referring to the sodium carbonate salts occurring in the deserts of Egypt, not the [[nitratine]] (nitrated sodium salts) typically occurring in the deserts of [[Chile]] (classically known as "Chilean saltpeter" and variants of this term).<ref name="oed"/><ref>{{Cite web |url=http://www.balashon.com/2008/07/neter-and-nitrogen.html |title=neter and nitrogen |last1=Curwin |first1=David |year=2008}}</ref>{{self-published inline|date=December 2021}}

A term ({{lang|grc|ἀφρόνιτρον}}, {{lang|grc-Latn|aphronitron}} or [[aphronitre]]) which translates as "foam of niter" was a regular purchase in a fourth-century AD series of financial accounts, and since it was expressed as being "for the baths" was probably used as soap.<ref>More conventional soap also appears in the accounts but was more expensive: John Matthews, ''The Journey of Theophanes'', Yale UP 2006</ref>

Niter was used to refer specifically to nitrated salts known as various types of [[saltpeter (disambiguation)|saltpeter]] (only nitrated salts were good for making gunpowder) by the time niter and its derivative [[nitric acid]] were first used to name the element [[nitrogen]], in 1790.<ref>{{oed|nitrogen}}</ref>

== Availability ==
{{See also|Potassium nitrate#Historical production}}
Because of its ready solubility in water, niter is most often found in arid environments and often in conjunction with other soluble minerals like [[halide]]s, [[iodate]]s, [[borate]]s, [[gypsum]], and rarer carbonates and sulphates.<ref>{{cite book |last1=Reeves |first1=C. C. |chapter=Economic Significance of Playa Lake Deposits |title=Modern and Ancient Lake Sediments |date=24 November 1978 |pages=279–290 |doi=10.1002/9781444303698.ch15|isbn=9780632002344 }}</ref><ref>{{cite journal |last1=Ericksen |first1=G.E. |year=1983 |title=The Chilean Nitrate Deposits: The origin of the Chilean nitrate deposits, which contain a unique group of saline minerals, has provoked lively discussion for more than 100 years |journal=American Scientist |volume=71 |number=4 |pages=366–374 |jstor=27852136}}</ref> 

Niter occurs naturally in certain places like the "Caves of Salnitre" ([[Collbató]]) known since the Neolithic. In the "Cova del Rat Penat", [[guano]] (bat excrements) deposited over thousands of years became saltpeter after being [[Leaching (pedology)|leached]] by the action of rainwater.{{citation needed|date=January 2022}}

In 1783, [[Giuseppe Maria Giovene]] and [[Alberto Fortis]] together discovered a "natural nitrary" in a [[sinkhole|doline]] close to [[Molfetta]], Italy, named [[Pulo di Molfetta]]. The two scientists discovered that niter formed inside the walls of the caves of the doline, under certain conditions of humidity and temperature.<ref>{{cite journal |title=Necrologia – Giuseppe Maria Giovene – Arciprete della Cattedrale Chiesa di Molfetta |author=Pietro Filioli |journal=Annali Civili del Regno delle Due Sicilie |year=1837 |volume=25, gennaio e febbraio |publisher=Tipografia del Real Ministero degli Affari Interni nel Reale Albergo de' Poveri |url=https://books.google.com/books?id=CC1FAAAAYAAJ&pg=PA35 |page=39|language=it}}</ref> After the discovery, it was suggested that manure could be used for agriculture, in order to increase the production, rather than to make gunpowder.<ref>{{Cite web |url=https://books.google.com/books?id=hr3g4qMtHfsC&pg=PA301 |title = Opuscoli scelti sulle scienze e sulle arti tratti dagli Atti delle Accademie, e dalle altre Collezioni filosofiche, e letterarie, e dalle opere più recenti inglesi, tedesche, francesi, latine, e italiane, e da manoscritti originali, e inediti: 12 |year=1789 |language=it}}</ref> The discovery was challenged by scholars until chemist [[Giuseppe Vairo (chemist)|Giuseppe Vairo]] and his pupil [[Antonio Pitaro]] confirmed the discovery. Naturalists sent by academies from all Europe came in large number to visit the site; since niter is a fundamental ingredient in the production of gunpowder, these deposits were of considerable strategic interest.<ref name="Elogio">{{cite journal |title=Elogio storico del canonico arciprete Giuseppe Maria Giovene |author=Andrea Tripaldi |journal=Memorie di Matematica e di Fisica della Società Italiana delle Scienze Residente in Modena |year=1841 |publisher= Tipi della R. D. Camera |location=Modena |volume=22 |url=https://books.google.com/books?id=0mmRYNPjNBAC&pg=PR1 |language=it }}</ref>{{rp|8–10}} The government started extraction. Shortly thereafter, Giovene discovered niter in other caves of [[Apulia]].<ref name="Elogio" />{{rp|9–10}}<ref>{{cite book |title=Lettera del Sig. canonico D. Giuseppe Maria Giovene, Vicario generale di Molfetta, al Sig. Abate Alberto Fortis, contenente varie osservazioni sulla nitrosità naturale della Puglia |author=Giuseppe Maria Giovene |date=7 August 1784 |location=[[Molfetta]] |url=https://books.google.com/books?id=hr3g4qMtHfsC&pg=PA309 |language=it}}</ref> The remnants of the extraction plant is a site of [[industrial archaeology]], although currently not open to tourists.<ref>{{Cite web |url=https://www.molfettafree.it/content_/zoom.asp?id_news=7117|title=PER VEDERE IL PULO DI MOLFETTA ACCONTENTATEVI DI ARRAMPICARVI! |website=molfettafree.it}}{{Dead link |date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

== Similar minerals ==
Related minerals are soda niter ([[sodium nitrate]]), ammonia niter or [[gwihabaite]] ([[ammonium nitrate]]), nitrostrontianite ([[strontium nitrate]]), nitrocalcite ([[calcium nitrate]]), nitromagnesite ([[magnesium nitrate]]), nitrobarite ([[barium nitrate]]) and two copper nitrates, [[gerhardtite]] and buttgenbachite; in fact all of the natural elements in the first three columns of the [[periodic table]] and numerous other cations form nitrates which are uncommonly found for the reasons given, but have been described. Niter was used to refer specifically to nitrated salts known as [[Saltpeter (disambiguation)|various types of saltpeter]] (only nitrated salts were good for making [[gunpowder]]) by the time niter and its derivative [[nitric acid]] were first used to name the element [[nitrogen]], in 1790.{{citation needed|date=January 2022}}

== See also ==
* {{Annotated link|Caliche}}
* [[Nitratine]] - Sodium based fertilizer

== References ==
{{reflist}}

== External links ==
{{commons category}}

* [http://www.balashon.com/2008/07/neter-and-nitrogen.html Etymology of "niter"]
* [https://web.archive.org/web/19970430135256/http://xroads.virginia.edu/~HYPER/POE/cask.html Poe's ''The Cask of Amontillado'']

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[[Category:Nitrate minerals]]
[[Category:Potassium minerals]]
[[Category:Orthorhombic minerals]]
[[Category:Minerals in space group 36]]
[[Category:Potash]]
[[Category:History of mining]]
[[Category:Nitrogen]]
[[Category:Saltpeter works| ]]