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[[Image:Argentite-unit-cell-3D-balls.png|thumb|The unit cell of '''argentite''']]
[[Image:Argentite-unit-cell-3D-balls.png|thumb|The unit cell of '''argentite''']]


In [[mineral]]ogy, '''argentite''' (from the [[Latin]] ''argentum'', silver) is [[Cubic crystal system|cubic]] [[silver sulfide]] (Ag<sub>2</sub>S), which can only exist at temperatures above 173&nbsp;°C,<ref>[http://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Argentit Mineralienatlas Lexikon - Argentit (in German)]</ref> 177&nbsp;°C<ref>[http://www.mindat.org/min-326.html] Argentite mindat.org:mineral information and data.</ref> or 179&nbsp;°C.<ref>[http://www.webmineral.com/data/Argentite.shtml Argentite on Webmineral]</ref> When it cools to ordinary temperatures it turns into its [[monoclinic]] [[Polymorphism (materials science)|polymorph]], [[acanthite]].<ref>[http://www.mindat.org/min-326.html] Argentite mindat.org:mineral information and data.</ref><ref>[http://www.webmineral.com/data/Argentite.shtml Argentite on Webmineral]</ref> Argentite belongs to the [[galena]] group.
In [[mineralogy]], '''argentite''' (from the [[Latin]] ''argentum'', silver) is [[Cubic crystal system|cubic]] [[silver sulfide]] (Ag<sub>2</sub>S), which can only exist at temperatures above 173&nbsp;°C,<ref name=de>[http://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Argentit Mineralienatlas Lexikon - Argentit (in German)]</ref> 177&nbsp;°C<ref name=Mindat>[http://www.mindat.org/min-326.html] Argentite mindat.org:mineral information and data.</ref> or 179&nbsp;°C.<ref name=Webmin>[http://www.webmineral.com/data/Argentite.shtml Argentite on Webmineral]</ref> When it cools to ordinary temperatures it turns into its [[monoclinic]] [[Polymorphism (materials science)|polymorph]], [[acanthite]].<ref name=Mindat/><ref name=Webmin/> Argentite belongs to the [[galena]] group.


The name "argentite" sometimes also refers to [[pseudomorph]]s of argentite: specimens of acanthite which still display some of the outward signs of the cubic crystal form, even though their actual crystal structure is monoclinic due to the lower temperature.<ref>[http://www.mindat.org/min-326.html] Argentite mindat.org:mineral information and data.</ref><ref>[http://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Argentit Mineralienatlas Lexikon - Argentit (in German)]</ref> This form of acanthite is occasionally found as uneven [[cube]]s and [[octahedron|octahedra]], but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre.{{sfn|Spencer|1911}}
The name "argentite" sometimes also refers to [[pseudomorph]]s of argentite: specimens of acanthite which still display some of the outward signs of the cubic crystal form, even though their actual crystal structure is monoclinic due to the lower temperature.<ref name=Mindat/><ref name=de/> This form of acanthite is occasionally found as uneven [[cube]]s and [[octahedron|octahedra]], but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre.{{sfn|Spencer|1911}}


[[Cleavage (crystal)|cleavage]], which is so prominent a feature in galena, here presents only in traces. The mineral is perfectly [[Sectility|sectile]] and has a shining streak; [[hardness]] 2.5, [[specific gravity]] is 7.2–7.4. It occurs in mineral veins, and when found in large masses, as in is [[Mexico]] and in the [[Comstock Lode]] in [[Nevada]], it forms an important [[ore]] of silver. The mineral was mentioned in 1529 by [[G. Agricola]], but the name ''argentite'' was not used till 1845 and is due to [[W. Haidinger]]. Old names for the species are ''Glaserz'', ''silver-glance'' and ''vitreous silver''. A related copper-rich mineral occurring e.g. in [[Jalpa, Zacatecas]], [[Mexico]], is known as [[jalpaite]].{{sfn|Spencer|1911}}
[[Cleavage (crystal)|cleavage]], which is so prominent a feature in galena, here presents only in traces. The mineral is perfectly [[Sectility|sectile]] and has a shining streak; [[hardness]] 2.5, [[specific gravity]] is 7.2–7.4. It occurs in mineral veins, and when found in large masses, as in is [[Mexico]] and in the [[Comstock Lode]] in [[Nevada]], it forms an important [[ore]] of silver. The mineral was mentioned in 1529 by [[G. Agricola]], but the name ''argentite'' was not used till 1845 and is due to [[W. Haidinger]]. Old names for the species are ''Glaserz'', ''silver-glance'' and ''vitreous silver''. A related copper-rich mineral occurring e.g. in [[Jalpa, Zacatecas]], [[Mexico]], is known as [[jalpaite]].{{sfn|Spencer|1911}}
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==Rejection by the International Mineralogical Association==
==Rejection by the International Mineralogical Association==


The [[International Mineralogical Association]] has decided to reject argentite as a proper mineral,<ref>[http://www.webmineral.com/data/Argentite.shtml Argentite on Webmineral]</ref> possibly due to its instability in normal air temperatures.{{citation needed|date=June 2013}}
The [[International Mineralogical Association]] has decided to reject argentite as a proper mineral.<ref name=Webmin/>

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==External links==
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==References==
==References==
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{{reflist}}


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*{{EB1911|first=Leonard James |last=Spencer|wstitle=Argentite}}
(Note: Some references are repeated above to protect them against damage by an ill-conceived bot which compresses merged reference tags
into a non-editable form).


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==External links==
;Attribution
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*{{EB1911|first=Leonard James |last=Spencer|wstitle=Argentite}}


{{ores}}
{{ores}}

Revision as of 14:00, 18 July 2015

Argentite sample
The unit cell of argentite

In mineralogy, argentite (from the Latin argentum, silver) is cubic silver sulfide (Ag2S), which can only exist at temperatures above 173 °C,[1] 177 °C[2] or 179 °C.[3] When it cools to ordinary temperatures it turns into its monoclinic polymorph, acanthite.[2][3] Argentite belongs to the galena group.

The name "argentite" sometimes also refers to pseudomorphs of argentite: specimens of acanthite which still display some of the outward signs of the cubic crystal form, even though their actual crystal structure is monoclinic due to the lower temperature.[2][1] This form of acanthite is occasionally found as uneven cubes and octahedra, but more often as dendritic or earthy masses, with a blackish lead-grey color and metallic lustre.[4]

cleavage, which is so prominent a feature in galena, here presents only in traces. The mineral is perfectly sectile and has a shining streak; hardness 2.5, specific gravity is 7.2–7.4. It occurs in mineral veins, and when found in large masses, as in is Mexico and in the Comstock Lode in Nevada, it forms an important ore of silver. The mineral was mentioned in 1529 by G. Agricola, but the name argentite was not used till 1845 and is due to W. Haidinger. Old names for the species are Glaserz, silver-glance and vitreous silver. A related copper-rich mineral occurring e.g. in Jalpa, Zacatecas, Mexico, is known as jalpaite.[4]

Rejection by the International Mineralogical Association

The International Mineralogical Association has decided to reject argentite as a proper mineral.[3]

References

  1. ^ a b Mineralienatlas Lexikon - Argentit (in German)
  2. ^ a b c [1] Argentite mindat.org:mineral information and data.
  3. ^ a b c Argentite on Webmineral
  4. ^ a b Spencer 1911.
  •  This article incorporates text from a publication now in the public domain: Spencer, Leonard James (1911). "Argentite". In Chisholm, Hugh (ed.). Encyclopædia Britannica (11th ed.). Cambridge University Press.
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