Ichnusaite

{{Infobox mineral | name = Ichnusaite | boxwidth = | boxbgcolor = | image = | imagesize = | alt = | caption = | category = Molybdate minerals | formula = Th(MoO4)2•3H2O | IMAsymbol = Ich<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 = | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = ''P2''1/''b'' | unit cell = a = 9.68, b = 10.38 c = 9.38 [Å], β = 90.00° (approximated) Z = 4 | color = Colorless | colour = | habit = | twinning = | cleavage = {100}, perfect | fracture = | tenacity = Brittle | mohs = | luster = Pearly adamantine | streak = | diaphaneity = | gravity = | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = 25px Radioactive | prop1 = | prop1text = | references = <ref name=AM/><ref name=Mindat/><ref name=Mineralienatlas>[https://www.mineralienatlas.de/lexikon/index.php/MineralData?mineral=Ichnusaite Mineralienatlas]</ref> }} '''Ichnusaite''' (pronounced iknusa-ait) is a very rarely found mineral.<ref name=Mindat>{{cite web|url=http://www.mindat.org/min-45998.html |title=Ichnusaite- Mindat.org |website=Mindat.org |accessdate=2016-03-06}}</ref> Ichnusaite is a natural compound of thorium and molybdenum with the formula Th(MoO4)2·3H2O. It was discovered in Su Seinargiu, Sarroch, Cagliari, Sardegna, Italy in 2013.<ref name=AM>{{Cite journal|title = Ichnusaite, Th(MoO4)2·3H2O, the first natural thorium molybdate: Occurrence, description, and crystal structure|url = http://ammin.geoscienceworld.org/content/99/10/2089|journal = American Mineralogist|date = 2014-10-01|issn = 0003-004X|pages = 2089–2094|volume = 99|issue = 10|doi = 10.2138/am-2014-4844|language = en|first1 = Paolo|last1 = Orlandi|first2 = Cristian|last2 = Biagioni|first3 = Luca|last3 = Bindi|first4 = Fabrizio|last4 = Nestola|s2cid = 97061833|access-date = 2016-02-13|archive-url = https://web.archive.org/web/20160521090233/http://ammin.geoscienceworld.org/content/99/10/2089|archive-date = 2016-05-21|url-status = dead|url-access = subscription}}</ref> The name is from the old Greek name of Sardinia, Ιχνουσσα, Ichnusa.<ref>{{Cite web|title=Ichnusaite|url=https://www.mindat.org/show.php?id=45998&ld=1|access-date=2021-05-07|website=www.mindat.org}}</ref> This locality is also a place of discovery of the second natural thorium molybdate - nuragheite.<ref>{{cite web|url=http://www.mindat.org/min-46000.html |title=Nuragheite - Mindat.org |website=Mindat.org |accessdate=2016-03-06}}</ref>

==Occurrence and association== Muscovite, nuragheite, and xenotime-(Y) are the associates of ichnusaite.<ref name=AM/>

==Notes on chemistry== Ichnusaite is chemically pure.<ref name=AM/>

==Crystal structure== The main features of the crystal structure of ichnusaite are:<ref name=AM/> * electroneutral Th(MoO4)2(H2O)2 (100) sheets * ThO7(H2O)2 and MoO4 polyhedra polymerize to give the above sheets * sheets are stacked along [100] and held by hydrogen bonds ==Bibliography== * Orlandi, P., Biagioni, C., Bindi, L. und Nestola, F. (2013) Ichnusaite, IMA 2013- 087. CNMNC Newsletter No. 18, December 2013, page 3255; Mineralogical Magazine, 77, 3249-325 * http://rruff.geo.arizona.edu/AMS/result.php?mineral=Ichnusaite * https://web.archive.org/web/20160521090233/http://ammin.geoscienceworld.org/content/99/10/2089 * https://arpi.unipi.it/handle/11568/638691#.Vr93OUKuAt4 * http://www.degruyter.com/dg/viewarticle/j$002fammin.2014.99.issue-10$002fam-2014-4844$002fam-2014-4844.xml * https://www.bbc.com/news/science-environment-35569659

==References== {{reflist}}

Category:Molybdate minerals Category:Thorium minerals Category:Monoclinic minerals Category:Trihydrate minerals Category:Minerals in space group 14 Category:Minerals described in 2014