View source for Parisite-(Ce)

{{Redirect-distinguish|Parisite|Parasite}}{{Infobox mineral
| name        = Parisite
| boxwidth    = 
| boxbgcolor  = 
| image       = Parisite-39471.jpg
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| caption     = Parisite from Muzo, Vasquez-Yacopí Mining District, [[Boyacá Department]], Colombia, size: 1.3 x 1 x .7 cm
| category    = [[Carbonate]]
| formula     = {{chem2|[[calcium|Ca]]([[cerium|Ce]],[[lanthanum|La]])2([[carbon|C]][[oxygen|O]]3)3[[fluorine|F]]2}}
| IMAsymbol   = Pst<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   = 537.24 g/mol
| strunz      = 5.BD.20b
| dana        = 16a.01.05.01
| system      = [[Monoclinic]]
| class       = Domatic (m) <br/><small>(same [[H-M symbol]])</small>
| symmetry    = ''Cc''
| unit cell   = a = 12.305&nbsp;Å, <br/>b = 7.1056&nbsp;Å, <br/>c = 28.2478&nbsp;Å; <br/>β = 98.246°; Z&nbsp;=&nbsp;12
| color       = Brown, brownish yellow, gray-yellow, grayish yellow, yellow, waxy yellow, colourless to yellow in transmitted light
| colour      = 
| habit       = [[Acicular (crystal habit)|Acicular]]
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| mohs        = {{frac|4|1|2}}
| luster      = [[Vitreous lustre|Vitreous]] - [[Greasy (lubrication)|greasy]]
| streak      = White
| diaphaneity = Transparent to translucent 
| gravity     = 4.34
| density     = 4.38
| polish      = 
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| references  = <ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Parisite-%28Ce%29 Mineralienatlas]</ref><ref>{{Cite web|url=http://www.mindat.org/min-3120.html|title = Parisite-(Ce)}}</ref><ref>{{Cite web|url=http://webmineral.com/data/Parisite-(Ce).shtml|title = Parisite-(Ce) Mineral Data}}</ref>
}}

'''Parisite''' is a rare [[mineral]] consisting of [[cerium]], [[lanthanum]] and [[calcium]] [[Fluorine|fluoro]]-[[carbonate]], {{chem2|[[calcium|Ca]]([[cerium|Ce]],[[lanthanum|La]])2([[carbon|C]][[oxygen|O]]3)3[[fluorine|F]]2}}. Parisite is mostly parisite-(Ce), but when [[neodymium]] is present in the structure the mineral becomes parisite-(Nd).

It is found only as [[crystal]]s, which belong to the [[hexagonal (crystal system)|trigonal]] or [[monoclinic]] pseudo-hexagonal system and usually have the form of acute double [[pyramid]]s terminated by the basal planes; the [[face]]s of the hexagonal pyramids are [[:wikt:striated|striated]] horizontally, and parallel to the [[basal plane]] there is a perfect [[cleavage (crystal)|cleavage]]. The crystals are hair-brown in color and are [[translucent]]. The [[Mohs scale of mineral hardness|hardness]] is 4.5 and the [[specific gravity]] is 4.36. Light which has traversed a crystal of parisite exhibits a characteristic [[absorption spectrum]]. 

At first, the only known occurrence of this mineral was in the famous [[emerald]] [[mining|mine]] at Muzo in [[Colombia]], [[South America]], where it was found by J.J. Paris, who rediscovered and worked the mine in the early part of the 19th century; here it is associated with emerald in a [[bituminous limestone]] of [[Cretaceous]] age. 

Closely allied to parisite, and indeed first described as such, is a mineral from the [[nepheline]]-[[syenite]] district of [[Julianehaab]] in south [[Greenland]]. To this the name [[synchysite]] has been given. The crystals are [[rhombohedral]] (as distinct from hexagonal; they have the composition {{chem2|CeFCa(CO3)2}}, and [[specific gravity]] of 2.90. At the same locality there is also found a [[barium]]-parisite, which differs from the Colombian parisite in containing barium in place of calcium, the formula being {{chem2|(CeF)2[[barium|Ba]](CO3)3}}: this is named cordylite on account of the club-shaped form of its hexagonal crystals. [[Bastnasite]] is a cerium lanthanum and neodymium fluoro-carbonate {{chem2|(CeF)CO3}}, from Bastnas, near Riddarhyttan, in Vestmanland, Sweden, and the [[Pikes Peak]] region in [[Colorado]], United States.

==References==
{{Reflist}}

==External links==
{{Commons category}}
*{{cite encyclopedia|url=http://www.handbookofmineralogy.org/pdfs/parisite-(Ce).pdf
 |title=Parisite-(Ce) |encyclopedia=Handbook of Mineralogy |editor1-first=John W. |editor1-last=Anthony|editor2-first=Richard A. |editor2-last=Bideaux|editor3-first=Kenneth W. |editor3-last=Bladh|editor4-first= Monte C. |editor4-last=Nichols |publisher=Mineralogical Society of America|location=Chantilly, VA |year=1990–2013}}

{{1911|wstitle=Parisite|volume=20|page=825}}

[[Category:Calcium minerals]]
[[Category:Lanthanide minerals]]
[[Category:Carbonate minerals]]
[[Category:Monoclinic minerals]]
[[Category:Minerals in space group 9]]