{{Short description|Silicate mineral}} {{Infobox mineral | name = Tinaksite | category = Silicate mineral | boxwidth = | boxbgcolor = | image = Tinaksite, Charoite-543035.png | imagesize = 260 | caption = Tinaksite (brown) and associated charoite (lilac). | formula = {{chem2|K2Na(Ca,Mn(2+))2TiO[Si7O18(OH)]}} | IMAsymbol = Tnk<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 = 9.DG.75 | system = Triclinic | class = Pinacoidal ({{Overline|1}}) <br/><small>(same H-M symbol)</small> | symmetry = ''P''{{Overline|1}} | color = Pink, pale yellow, light brown | habit = Fibrous, crystalline or prismatic, crystalline, or radial, crystalline | twinning = | cleavage = Perfect in one direction, indistinct in one direction | fracture = | mohs = 6 | luster = Vitreous to glassy | refractive = nα = 1.593 nβ = 1.621 nγ = 1.666 | opticalprop = Biaxial (+) | birefringence = δ = 0.073 | pleochroism = | streak = White | gravity = 2.82 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = | references = <ref name=Webmineral>{{Cite web|url=http://webmineral.com/data/Tinaksite.shtml|title=Tinaksite Mineral Data}}</ref><ref name=Mindat>{{Cite web|url=http://www.mindat.org/min-3966.html|title = Tinaksite}}</ref><ref>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Tinaksite Mineralienatlas]</ref> }}
'''Tinaksite''' (chemical formula {{chem2|K2Na(Ca,Mn(2+))2TiO[Si7O18(OH)]}})<ref name=Mindat/> is a mineral found in northern Russia. Tinaksite can be grayish-white, yellowish, orange, or brown,<ref name=Webmineral/> and it is often found in charoite.<ref>{{Cite web|url=http://www.galleries.com/minerals/silicate/tinaksit/tinaksit.htm|title = TINAKSITE (Potasium Sodium Calcium Manganese Titanium Iron Oxide Silicate Hydroxide)}}</ref> Its name is derived from its composition: titanium ('''Ti'''), sodium ('''Na''') potassium ('''K''') and silicon ('''Si'''). The International Mineralogical Association first recognized tinaksite as a mineral in 1965.
==References== {{Reflist}}
==External links== *{{cite journal | url = http://rruff.geo.arizona.edu/doclib/zk/vol189/ZK189_195.pdf| title = The crystal structure of tokkoite and its relation to the structure of tinaksite | first1 = I. V. | last1 = Rozhdestvenskaya | first2 = L. V. | last2= Nikishova | first3 = Y. D. | last3 = Lazebnik | first4 = K. A. | last4 = Lazebnik | journal = Zeitschrift für Kristallographie | pages =195–204 | year = 1989 | volume = 189 | issue = 1–4 | doi = 10.1524/zkri.1989.189.14.195 | s2cid = 53544093 }}
Category:Calcium minerals Category:Sodium minerals Category:Potassium minerals Category:Inosilicates Category:Gemstones Category:Triclinic minerals Category:Minerals in space group 2 Category:Minerals described in 1965