Lanthanite

{{short description|Group of isostructural rare earth element carbonate minerals}} {{distinguish|lanthanide}} {{Infobox mineral | name = Lanthanite-(La), Lanthanite-(Nd), Lanthanite-(Ce) | boxwidth = | boxbgcolor = | image = LanthaniteNd R060993 Sample Photo 10941 M.jpg | imagesize = 260px | alt = | caption = Lanthanite-(Nd) from Mitsukoshi, Hizen-cho, Karatsu City, Saga Prefecture, Japan. | category = Carbonate minerals | formula = (''REE'')₂(CO₃)₃·8(H₂O) | IMAsymbol = Ltn<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> | strunz = 5.CC.25 | dana = (La): 15.04.02.01 <br/>(Nd): 15.04.02.02 <br/>(Ce): 15.04.02.03 | system = Orthorhombic | class = Dipyramidal (mmm) <br/>H-M symbol: (2/m 2/m 2/m) | symmetry = ''Pbnb'' | unit cell = a = 9.476(4)–9.483(6) <br/>b = 16.940(8)–16.938(11) <br/>c = 8.942(4)–8.965(3)&nbsp;[Å], Z&nbsp;=&nbsp;4 | molweight = | color = Pale pink to purple | colour = | habit = Platy | twinning = Common on {101} | cleavage = Micaceous, perfect on {101} | fracture = Uneven | tenacity = Sectile | mohs = 2.5 | luster = Vitreous to pearly | streak = White | diaphaneity = | gravity = | density = 2.78–2.84 (measured), 2.79–2.816 (calculated) | polish = | opticalprop = Biaxial (−) | refractive = | birefringence = | pleochroism = | 2V = 58°–61° (measured), 60°–63.5° (calculated) | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref>[http://www.mindat.org/min-46.html Lanthanite on Mindat]</ref> }}

'''Lanthanites''' are a group of isostructural rare earth element (REE) carbonate minerals. This group comprises the minerals lanthanite-(La),<ref>Haidinger W (1845) Zweite Klasse: Geogenide. II. Ordnung. Baryte. III. Cerebaryt. Lanthanit., in Handbuch der Bestimmenden Mineralogie, Bei Braumüller and Seidel (Wien) 499–506.</ref><ref>Nickel E H, Mandarino J A (1987) Procedures involving the IMA Commission on New Minerals and Mineral Names and guidelines on mineral nomenclature, American Mineralogist 72, 1031–1042.</ref> lanthanite-(Ce),<ref>Bevins R E, Rowbotham G, Stephens F S, Turgoose S, Williams P A (1985) Lanthanite-(Ce), (Ce,La,Nd)₂(CO₃)₃·8H₂O, a new mineral from Wales, U.K. American Mineralogist 70, 411–413.</ref> and lanthanite-(Nd).<ref>Roberts A C, Chao G Y, Cesbron F (1980) Lanthanite-(Nd), a new mineral from Curitiba, Parana, Brazil, Geological Survey of Canada Paper 80-1C, 141–142.</ref> This mineral group has the general chemical formula of (''REE'')₂(CO₃)₃·8(H₂O). Lanthanites include La, Ce, and Nd as major elements and often contain subordinate amounts of other REEs including praseodymium (Pr), samarium (Sm), europium (Eu) and dysprosium (Dy).<ref>The Canadian Mineralogist 45 (2007) 1389–1396.</ref> The lanthanite crystal structure consists of layers of tenfold-coordinated REE-oxygen (O) polyhedra and carbonate ({{chem2|CO3(2-)}}) groups connected by hydrogen bonds to interlayer water molecules, forming a highly hydrated structure.<ref>Morrison, S. M., Andrade, M. B., Wenz, M. D., Domanik, K. J., & Downs, R. T. (2013). Lanthanite-(Nd), Nd₂(CO₃)·3.8H₂O. Acta Crystallographica Section E: Structure Reports Online, 69(3), i15–i16. {{doi|10.1107/S1600536813003164}}</ref>

==Origin and formation==

Lanthanites are frequently found as secondary minerals formed by the weathering of other minerals and occur as scales or tabular crystals. Originally identified at Bastnäs, Sweden,<ref>Berzelius, J. (1825). Taschenbuch für die gesamte Mineralogie mit Hinsicht auf die neuesten Entdeckungen, 19, 193–218.</ref> they have subsequently been found in New Zealand,<ref>Graham, I.T., Pogson, R.E.,Colchester, D.M., Hergt, J. Martin, R. & Williams, P.A. (2007): Pink Lanthanite-(Nd) from Whitianga Quarry, Coromandel Peninsula, New Zealand. Canadian Mineralogist. 45: 1389–1396</ref> Japan,<ref>American Mineralogist: 71(7–8): 1028–1033.</ref> Madagascar,<ref>Behier, J. (1960): Contribution à la mineralogie de Madagascar. Annales Géologiques de Madagascar XXIX, Tananarive, p 18</ref> Wales,<ref>Amer.Min.(1985) 70, 411–413</ref> China,<ref>Zhang Peishan, Yang Zhuming, Tao Kejie, and Yang Xueming (1996): "Mineralogy and Geology of Rare Earths in China", Science Press (Beijing), 226 pp.</ref> France,<ref>Remy, P., Gatel, P., Meisser, N. (2014): Indice à terres rares de Mosset (Pyrénées-Orientales). Le Cahier des Micromonteurs, 1-2014, 3–17.</ref> Germany,<ref>Gröbner, J., Hajek, W., Junker, R. & Nikoleizig, J. (2011): Neue Mineralschätze des Harzes. Papierflieger Verlag GmbH, Clausthal-Zellerfeld, Germany, 127 pp.</ref> Greenland,<ref>Petersen, O. V. and Secher, K. (1993): The minerals of Greenland, The Mineralogical Record, Vol. 24(2), 1–65</ref> Finland,<ref>Sotka, P. 1984. Juuka, Panjavaara: Ce-La-Sr-mineraalien esiintyminen karbonaattijuonissa. Outokumpu OY raportti 070/4312 08A/PMS/1984.</ref> Canada,<ref>Horváth, L. & Pfenninger-Horváth, E. (2000) I minerali di Mont-Saint-Hilaire (Québec, Canada) Rivista Mineralogica Italiana, XXIV, 140–202.</ref> Austria,<ref>G. Niedermayr, I. Praetzel: Mineralien Kärntens, 1995.</ref> Romania,<ref>Szakáll, S. & Kristály, F., Eds. (2010): Mineralogy of Székelyland, Eastern Transylvania, Romania. Csík County Nature and Conservation Society, Miercurea-Ciuc, Romania, 321 pp.</ref> Norway,<ref>Sæbø, P.Chr. (1961): Contribution to the mineralogy of Norway. No.11. On lanthanite in Norway. Norsk Geologisk Tidsskrift. 41: 311–317</ref> Brazil,<ref>Roberts, A.C., G.Y. Chao, and F. Cesbron (1980) Lanthanite-(Nd), a new mineral from Curitiba, Paran ́a, Brazil. Geol. Surv. Canada, Paper 80-1C, 141–142.</ref> and the United States.<ref>"Minerals of Colorado, updated & revised", p. 14, by Eckel, Edwin B., 1997.</ref>

Recently, a different mechanism of formation of lanthanites was discovered: Lanthanites also can form via a highly hydrated, nanoparticulate and poorly ordered carbonate precursor.<ref>Rodríguez Blanco, J.D., Vallina, B., Blanco, J.A. and Benning, L.G. (2014) The role of REE³⁺ in the crystallization of lanthanites. Mineralogical Magazine, 78, 1373–1380. [http://minmag.geoscienceworld.org/content/78/6/1373.full DOI: 10.1180/minmag.2014.078.6.03]</ref> The lifetime of this rare-earth bearing precursor as well as the kinetics of crystallization of the various REE-lanthanites are dependent on the specific trivalent rare-earth ion involved in the reaction. The times needed for lanthanites to fully crystallize increase linearly with the ionic potential of the trivalent rare-earth ion (La³⁺, Ce³⁺, Pr³⁺, Nd³⁺) present in their structure. The differences in these ion sizes and ionic potential as well as differences in dehydration energy of the trivalent rare-earth ions control the lifetime of the poorly ordered precursor and thus also the crystallization kinetics of the lanthanites. Furthermore, they also affect the structural characteristics (e.g. unit-cell dimensions and standard shape) of the crystals.

==References== {{Reflist}} ==Other sources== *[http://webmineral.com/data/Lanthanite-(Ce).shtml Webmineral data] *[http://www.mindat.org/min-2325.html Mindat with location data] *[http://rruff.info RRUFF Project]

==Further reading== *Miyawaki R, Matsubara S, Yokoyama K, Iwano S, Hamasaki K, Yukinori I (2003) Kozoite-(La), La(CO₃)(OH), a new mineral from Mitsukoshi, Hizen-cho, Saga Prefecture, Japan. Journal of Mineralogical and Petrological Sciences 98, 137–141. *Miyawaki, R., Matsubara, S., Yokoyama, K., Takeuchi, K., Terada, Y., & Nakai, I. (2000). Kozoite-(Nd), Nd(CO₃)(OH), a new mineral in an alkali olivine basalt from Hizen-cho, Saga Prefecture, Japan. American Mineralogist, 85(7–8), 1076–1081. *Sheard, E.R., Williams-Jones, A.E., Heiligmann, M., Pederson, C., Trueman, D.L. (2012) Controls on the concentration of zirconium, niobium, and the rare earth elements in the Thor Lake rare metal deposit, Northwest Territories, Canada. Economic Geology, 107(1), 81–104. *Nordrum, F. S. (2007): Nyfunn av mineraler i Norge 2006–2007. Stein 34 (2), 14–26. *Husdal, T. (2009): Ancylittmineraler i Norge. Norsk Bergverksmuseum Skrift 41, 33–42. *Larsen, A. O. (1994): Drusemineraler fra Solumsåsen pukkverk, Holmestrand. Stein 21 (2), 136–141. *Minerals of Georgia: Their properties and occurrences. Robert Cook GGWRD Bull 92. *American Mineralogist: 38: 1169–1183 *New Data on Minerals (2004): 39: 50–64. *Jensen (1978) Minerals of New York State.*Dana 6: 767; Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837–1892, Volume II: 242.*Rocks & Minerals: 6: 26; Rocks & Minerals: 10: 33–36, 58. *Handbook of Mineralogy — Anthony, Bideaux, Bladh, Nichols; Hess, F. L. 1908. Minerals of the rare-earth metals at Baringer Hill, Llano County, Texas. U.S. Geological Survey Bulletin 340. 286–294. *Schooner, Richard. (1958): The Mineralogy of the Portland–East Hampton–Middletown–Haddam Area in Connecticut (With a few notes on Glastonbury and Marlborough).

{{Authority control}}

Category:Lanthanide minerals Category:Carbonate minerals Category:Orthorhombic minerals Category:Minerals in space group 56