{{short description|Rare inosilicate mineral}} {{Infobox mineral | name = '''Yuksporite''' | boxwidth = | boxbgcolor = | image = Yuksporite-3.jpg | caption = Yuksporite from the Khibiny Massif, Kola Peninsula, Russia (4&nbsp;cm across) | category = Inosilicates | formula = see text | IMAsymbol = Yks<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 = 2,546.97 g/mol | strunz = 9.DG.95 | dana = 66.3.1.5 | system = Monoclinic | class = Prismatic (2/m) <br /><small>(same H-M symbol)</small> | symmetry = ''P''2/m | color = Brownish pink to rose-red to straw-yellow | habit = Fibrous, scaly or lamellar | twinning = | cleavage = | fracture = | tenacity = | mohs = {{frac|4|1|2}} to 5 | luster = Vitreous, silky | refractive = n<sub>α</sub> = 1.644, n<sub>γ</sub> = 1.660 | opticalprop = Biaxial | birefringence = | pleochroism = X pale rose-yellow, Y, Z rose-yellow | streak = Nearly white to white | gravity = 3.05 | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Semitransparent | other = Barely detectable radioactivity | references = <ref name = Dana>Gaines et al (1997) Dana’s New Mineralogy Eighth Edition. Wiley</ref><ref name = Mindat>{{mindat|id=4378|title = Yuksporite|access-date=8 August 2022}}</ref><ref name = Webmin>{{Cite web|last1=Barthelmy|first1=David|year=2014|url=http://www.webmineral.com/data/Yuksporite.shtml|access-date=8 August 2022|title = Yuksporite Mineral Data|website=Webmineral.com}}</ref><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=Yuksporite |url=http://www.handbookofmineralogy.org/pdfs/yuksporite.pdf |website=Handbook of Mineralogy |publisher=Mineral Data Publishing |access-date=8 August 2022 |date=2005 |archive-date=10 November 2022 |archive-url=https://web.archive.org/web/20221110132540/http://www.handbookofmineralogy.org/pdfs/Yuksporite.pdf |url-status=dead }}</ref><ref name="IMA">{{Cite web|url=http://rruff.info/ima|title=IMA Mineral List with Database of Mineral Properties}}</ref> }}

'''Yuksporite''' is a rare inosilicate mineral with double width, unbranched chains, and the complicated chemical formula {{chem2|K4(Ca,Na)14Sr2Mn(Ti,Nb)4(O,OH)4(Si6O17)2(Si2O7)3(H2O,OH)3}}.<ref name = "IMA" /> It contains the relatively rare elements strontium, titanium and niobium, as well as the commoner metallic elements potassium, calcium, sodium and manganese. As with all silicates, it contains groups of linked silicon and oxygen atoms, as well as some associated water molecules.

Yuksporite is a member of the umbite group that has just two known members, umbite, {{chem2|K2ZrSi>3O9*H2O}}, and yuksporite.<ref name = Mindat/> It was first reported in 1922, from nepheline syenite occurrences in the Kola Peninsula, Russia, and named by Alexander Fersman for the locality, near Mount Yukspor.<ref name = AM12>{{Cite journal |author=Schairer J F |year=1927 |journal=American Mineralogist |volume=12 |page=58 |url=http://www.minsocam.org/ammin/AM12/AM12_58.pdf |title=New Mineral Names: summarising Fersman A E (1923) Transactions of the Northern Scientific and Economic Expedition (16) 16-73}}</ref>

== Unit cell == Yuksporite was originally thought to be orthorhombic, space group unknown.<ref name = Dana/><ref name = Mindat/><ref name = HOM/> In 2004, however, the structure was solved using synchrotron radiation and found to be monoclinic 2/m with space group P2<sub>1</sub>/m.<ref name = Webmin/><ref name = AM89/> The monoclinic unit cell has two formula units per cell (Z = 2)<ref name = Webmin/> and side lengths a = 7.126&nbsp;Å, b = 24.913&nbsp;Å and c = 17.075&nbsp;Å, with the angle β between the a and c axes equal to 101.89°.<ref name = AM89>Krivovichev, Yakovenchuk, Armbruster, Dobelin, Pattison, Weber and Depmeier (2004) American Mineralogist 89:1561</ref>

== Appearance == The mineral is brownish pink, rose pink or yellowish in color, with a silky to vitreous luster and a nearly white streak. It occurs in semi-transparent fibrous, scaly or lamellar aggregates up to 10&nbsp;cm across.<ref name=Dana/>

== Properties == Yuksporite is a biaxial mineral, but most authors do not specify whether it is (+) or (-); the Handbook of Mineralogy<ref name = HOM/> gives it as (+). All agree, however, that the refractive indices are N<sub>x</sub> = 1.644 and N<sub>z</sub> = 1.660 (with N<sub>y</sub> unspecified), which are larger than those for quartz, but similar to those for tourmaline. Yuksporite shows pleochroism, with X pale rose-yellow, and Y, Z rose-yellow. It has a hardness of {{frac|4|1|2}} to 5, between fluorite and apatite, and specific gravity 3.05, similar to fluorite. It exhibits barely detectable radioactivity.<ref name = Webmin/>

== Occurrence and associations == The type locality is the Hackman Valley, Yukspor Mt, Khibiny Massif, Murmanskaja Oblast', Northern Region, Russia,<ref name = Mindat/> and type material is conserved at the Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, catalogue number 25847.<ref name = HOM/> The only occurrences reported by Mindat.org are in Russia. At the Khibiny massif it occurs in veins in nepheline syenite associated with titanite, pectolite, astrophyllite, biotite and aegirine.<ref name = AM12/> At the Murun Massif in the Sakha Republic it is associated with aegirine, kalsilite, potassic feldspar, titanite, lamprophyllite, wadeite and tausonite.<ref name = HOM/>

thumb|right|180px|Yuksporite from Russia

==References== {{reflist}}

== External links == * [http://rruff.geo.arizona.edu/AMS/viewJmol.php?id=03651 View molecule] in Jmol

{{commons category|Yuksporite}}

Category:Inosilicates Category:Potassium minerals Category:Strontium minerals Category:Manganese minerals Category:Monoclinic minerals Category:Minerals in space group 10