Английская Википедия:Feklichevite

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Шаблон:Short description Шаблон:Infobox mineral Feklichevite is a rare mineral of the eudialyte group with the formula Na11Ca9(Fe3+,Fe2+)2Zr3NbSi(Si3O9)2(Si9O27)2.[1][2] The original formula was extended to show the presence of cyclic silicate groups and presence of silicon at the M4 site, according to the nomenclature of eudialyte group.[3] When compared to other minerals of the group, feklichevite characterizes in the presence of ferric iron (thus similar to ikranite, mogovidite and fengchengite[2]) and dominance of calcium at the N4 site. Calcium is ordered in the structure and is also present at the M1 site.[1][3] Other iron-bearing minerals of the group are eudialyte, ferrokentbrooksite, georgbarsanovite, khomyakovite, labyrinthite, oneillite and rastsvetaevite, but they rather contain ferrous iron[2] Feklichevite name honors Russian mineralogist and crystallographer, V. G. Feklichev.[1]

Occurrence and association

Feklichevite was found in cancrinite syenite vein of pegmatoid type, that occurs in the Kovdor alkaline massif, Kola Peninsula, Russia. Feklichevite coexists with aegirine-diopside, cancrinite, potassic feldspar, pectolite, titanite, hematite, and руrrhоtitе.[1]

Notes on chemistry

Feklichevite has quite high admixtures of manganese and fluorine, with minor hafnium, strontium, titanium, cerium, and lanthanum.[1]

References

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  1. 1,0 1,1 1,2 1,3 1,4 Pekov, I.V., Ekimenkova, I.A., Chukanov, N.V., Rastsvetaeva, R.K., Kononkova, N.N., Pekova, N.A., and Zadov, A.E., 2001. Feklichevite Na11Ca9(Fe3+,Fe2+)2Zr3Nb[Si25O73](OH,H2O,Cl,O)5, a new mineral of the eudialyte group from Kovdor Massif, Kola peninsula. Zapiski Vserossijskogo Mineralogicheskogo Obshchestva 130(3), 55–65
  2. 2,0 2,1 2,2 Mindat, Feklichevite, http://www.mindat.org/min-11029.html
  3. 3,0 3,1 Johnsen, O., Ferraris, G., Gault, R.A., Grice, D.G., Kampf, A.R., and Pekov, I.V., 2003. The nomenclature of eudialyte-group minerals. The Canadian Mineralogist 41, 785–794