Voronkovite is a very rare mineralMindat, Voronkovite, http://www.mindat.org/min-32199.html of the eudialyte group with the chemical formula .Khomyakov, A.P., Nechelyustov, G.N., and Rastsvetaeva, R.K., 2010, Voronkovite, , a new mineral species of the eudialyte group from the Lovozero alkaline pluton, Kola Peninsula, Russia. Geology of Ore Deposits 51(8), 750–756 The formula is based on the simplified original one; it does not show the presence of cyclic silicate groups, but two M3- and M4-site silicon atoms are shown separately (basing on the nomenclature of the eudialyte groupJohnsen, 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). Voronkovite has lowered symmetry (space group R3, instead of more specific for the group R3m one), similarly to some other eudialyte-group members: aqualite, labyrinthite, oneillite and raslakite. The specific feature of voronkovite is, among others, strong enrichment in sodium.
Occurrence and association Voronkovite comes from an ultra-alkaline pegmatite of Mt. Alluaiv, Lovozero Massif, Kola Peninsula, Russia. It occurs with aegirine, lomonosovite, manganoneptunite, microcline, nepheline, shkatulkalite, sodalite, terskite, sphalerite and vuonnemite.
Notes on chemistry Voronkovite has additional impurities, not given in the formula. They include strontium, fluorine, potassium, lanthanum, neodymium (at the Mn site), niobium, and minor hafnium and aluminium.
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