Editing Analcime

{{Short description|Zeolite mineral}}
{{Infobox mineral
|boxbgcolor=#ae602d| name        = Analcime
| boxtextcolor = #fff
| category    = [[Tectosilicate]] [[minerals]], [[zeolite]] [[Mineral group|group]]
| image       = Analcime - Kahwan Mountain, Semnan, Iran.jpg
| imagesize   = 280px
| caption     = Reddish crystals of analcime up to 1.8 cm in size on matrix
| formula     = NaAlSi<sub>2</sub>O<sub>6</sub> · H<sub>2</sub>O
|IMAsymbol=Anl
| strunz      = 9.GB.05
| system      = [[Orthorhombic]]
| class       = Dipyramidal (mmm) <br />[[H-M symbol]]: (2/m 2/m 2/m)
| symmetry    = ''Ibca''
|molweight=220.15| color       = White, colorless, gray, pink, greenish, yellowish
| habit       = Typically in crystals, usually trapezohedrons, also massive to granular.
| twinning    = Polysynthetic on [001], [110]
| cleavage    = Indistinct on {001}, {010}, {100}
| fracture    = Uneven to subconchoidal
| mohs        = 5–5.5
| luster      = Vitreous
| refractive  = n = 1.479–1.493
| opticalprop = Isotropic; anomalously biaxial (−)
| pleochroism =None 
|fluorescence=Short UV = Greenish blueish white <br/>Long UV = Green, creamy white-yellow| streak      = White
| gravity     = 2.24–2.29
| fusibility  = 3.5
|diaphaneity=Transparent to subtransparent to translucent| other       = Weakly piezoelectric and pyroelectric; weakly electrostatic when rubbed or heated
}}

'''Analcime''' ({{IPAc-en|ə|ˈ|n|æ|l|s|iː|m|,_|-|s|aɪ|m}}; {{etymology|grc|''{{wikt-lang|grc|ἀνάλκιμος}}'' ({{grc-transl|ἀνάλκιμος}})|not strong}}) or '''analcite''' is a white, gray, or colorless [[tectosilicate]] mineral. Analcime consists of hydrated [[Sodium aluminosilicate|sodium aluminium silicate]] in cubic [[crystal]]line form. Its [[chemical formula]] is NaAlSi<sub>2</sub>O<sub>6</sub> · [[Water|H<sub>2</sub>O]]. Minor amounts of [[potassium]] and [[calcium]] substitute for sodium. A [[silver]]-bearing synthetic variety also exists (Ag-analcite). Analcime is usually classified as a [[zeolite]] mineral, but structurally and chemically it is more similar to the [[feldspathoid]]s.<ref name=":1" /> Analcime is not classified as an isometric crystal, as although the crystal structure appears to be isometric, it is usually off only by a fraction of an angle. However, there are truly isometric samples of the mineral, which makes its classification even more difficult.<ref name=":3">{{Cite web |title=Analcime (analcite): The zeolite mineral analcime information and pict |url=http://www.minerals.net/MineralDefinition.aspx?name=analcime |access-date=2022-12-29 |website=www.minerals.net |language=en-US}}</ref> Due to the differences between the samples being too slight, there's no merit from having multiple species names, so as a result analcime is a common example for minerals occurring in multiple crystal systems and space groups. It was first described by French geologist [[Déodat de Dolomieu]], who called it zéolithe dure, meaning hard zeolite. It was found in lava in [[Cyclopean Isles|Cyclops]], Italy. The mineral is [[International Mineralogical Association|IMA]] approved, and had been grandfathered, meaning the name analcime is believed to refer to a valid species til this day.<ref name=":0">{{Cite web |title=Analcime |url=https://www.mindat.org/min-210.html |access-date=2022-12-29 |website=www.mindat.org}}</ref>

== Properties ==
Analcime crystals always look pseudocubic.<ref name=":0" /> Its common crystal forms include trapezohedron, truncated trapezohedron with cubic faces, and more rarely either as a truncated trapezohedron, or the crystals can take the shape of a truncated cube that is typical to bixbyites.<ref name=":2" /> The crystals can occur either individually, as interconnected, form groups on plates or even in druzy form. Crystal masses can also form veins sometimes.<ref name=":3" /> Individual crystals are [[euhedral]], meaning they have well defined faces. When on a matrix, the mineral takes a granular habit, meaning the crystals become [[Euhedral and anhedral|anhedral]].<ref name=":4">{{Cite web |title=Analcime Mineral Data |url=http://www.webmineral.com/data/Analcime.shtml |access-date=2022-12-29 |website=www.webmineral.com}}</ref> The color of the mineral varies due to trace impurities. The mineral is weakly piezoelectric and pyroelectric, meaning it produces a weak electric charge when it's rubbed or heated, hence the name analcime.<ref name=":0" /> Other characteristics include the fact that the mineral can have a blueish white fluorescence when inspected under short UV light, and a creamy white-yellow one inspected under long UV light. It does not show any pleochroic or radioactive properties.<ref name=":4" /> Analyses regarding the mineral's symmetry vary in results, however the most prevalent one being tetragonal.<ref name=":3" /> The mineral usually has polysynthetic twins, which are only visible in thin sections when the specimen is inspected under polarized analyzed light.<ref name=":2" /> Analcime mainly consists of oxygen (50.87%), silicon (25.51%), aluminum (12.26%), sodium (10.44%) but otherwise has a negligible amount of hydrogen (0.92%) as well.<ref name=":4" /> The highest quality specimens take the form of a trapezohedron, and can reach up to 25&nbsp;cm. These specimens are associated with [[serandite]], [[aegyrine]] and [[natrolite]], and can be found at [[Mont Saint-Hilaire]], [[Quebec]]. Of the pinkish-white specimens, the mineral takes the shape of well-formed cubes which can exceed 10&nbsp;cm, originating from several sites in [[Val di Fassa]], [[Trentino]], Italy.<ref name=":2">{{Cite web |title=Analcime - Encyclopedia |url=https://www.le-comptoir-geologique.com/analcime-encyclopedia.html |access-date=2022-12-29 |website=www.le-comptoir-geologique.com}}</ref>

== Formation and associated minerals ==
Analcime occurs as a primary mineral in analcime [[basalt]] and other alkaline [[igneous rocks]]. It also occurs as cavity and vesicle fillings associated with [[prehnite]], [[calcite]], and zeolites. Analcime forms in [[sedimentary rocks]] at temperatures below about {{convert|100|C||sp=us}}, and so its presence indicates that the rock has experienced shallow [[diagenesis]].<ref name=":1" /> Although it is common in igneous rocks (namely basalts and [[Trachybasalt|trachy-basalts]]), it is more rarely found in [[phonolite]]s. Associations include zeolites, calcite and prehnite; however, it is also found in nepheline syenites and their pegmatites. It forms a series with [[pollucite]].<ref name=":2" />

== Locations ==
Well known locations for sourcing analcime include [[Croft, Leicestershire#Industry and Business|Croft Quarry]] in [[Leicestershire]], UK; the [[Cyclopean Islands]] east off [[Sicily]] and near Trentino in northern Italy; [[Victoria (Australia)|Victoria]] in Australia; [[Kerguelen Island]] in the [[Indian Ocean]]; in the [[Lake Superior]] copper district of [[Michigan]], Bergen Hill, [[New Jersey]], [[Golden, Colorado]], and at [[Searles Lake]], California in the United States; and at Cape Blomidon, [[Nova Scotia]] and Mont Saint-Hilaire, Quebec<ref name=":1">{{cite book |last1=Normand |first1=Charles |last2=Tarassoff |first2=Peter |title=Mineralogy and geology of the Poudrette quarry, Mont SaintHilaire, Quebec |date=2006 |publisher=Mineralogical Association of Canada |url=https://www.mcgill.ca/redpath/files/redpath/guidebook_4a_final2.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.mcgill.ca/redpath/files/redpath/guidebook_4a_final2.pdf |archive-date=2022-10-09 |url-status=live |access-date=12 March 2022}}</ref> in Canada; and in [[Iceland]], and in [[Namibia]].<ref>{{cite book |last1=Prothero |first1=Donald R. |last2=Schwab |first2=Fred |title=Sedimentary geology : an introduction to sedimentary rocks and stratigraphy |date=2004 |publisher=W.H. Freeman |location=New York |isbn=0716739054 |page=124 |edition=2nd}}</ref> Siberian samples from [[Nidym]] and [[Toura]] provide us with white crystals of 18&nbsp;cm. Samples of the Cyclopean Islands are known for their beautiful and clear crystals, just like the crystals of [[Kings Valley, Oregon|Kings Valley]] and [[Springfield, Oregon|Springfield]] in Oregon, which can reach up to 6&nbsp;cm. [[Coleman (Canada)|Coleman]], [[Alberta]] in Canada is known for producing beautiful red crystals.<ref name=":2" />

== Usage ==
Other than its aesthetic values, analcime currently presents no use. Crystallized specimens are sought after by collectors,<ref name=":2" /> and the mineral is hardly ever made into jewelry. The crystals made into jewelries are uncut and handcrafted.{{citation needed|date=December 2022}} It has lacking use as a microporous material. This is due to the fact that analcime has a compact structure and thus it has a strong resistance to diffusion of both molecules and cations. Analcime-bearing tuffs are sometimes used as building materials.<ref>{{Cite web |title=Analcime |url=http://www.iza-online.org/natural/Datasheets/Analcime/Analcime.html |access-date=2022-12-29 |website=www.iza-online.org}}</ref>

==See also==
* {{annotated link|List of minerals}}

== References ==
{{Reflist}}
* Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., {{ISBN|0-471-80580-7}}
* [https://web.archive.org/web/20041205170949/http://mineral.galleries.com/Minerals/silicate/analcime/analcime.htm Mineral Galleries]
* [http://www.mindat.org/min-210.html Mindat.org]
* [http://webmineral.com/data/Analcime.shtml Webmineral.com]

==External links==
{{Commons category|Analcime}}
*[http://helios.princeton.edu/zeomics/cgi-bin/view_structure.pl?src=iza&id=ANA structure type ANA]{{Dead link|date=September 2021 |bot=InternetArchiveBot |fix-attempted=yes }}

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[[Category:Zeolites]]
[[Category:Sodium minerals]]
[[Category:Aluminium minerals]]
[[Category:Orthorhombic minerals]]
[[Category:Minerals in space group 73]]