Golyshevite is a rare mineral of the

eudialyte group Eudialyte group is a group of complex trigonal zircono- and, more rarely, titanosilicate minerals with general formula (1)N(2)N(3)N(4)N(5)sub>3 (1a)M(1b)sub>3M(2)3M(4)Z3 i24O72'4X2, where N(1) and N(2) and N(3) and N(5) = Na+ and more rarely H3 ...

,Mindat, Golyshevite, http://www.mindat.org/min-27418.html with the formula Na₁₀Ca₃Ca₆Zr₃Fe₂SiNb(Si₃O₉)₂(Si₉O₂₇)₂CO₃(OH)₃•H₂O. The original formula was extended to show both the presence of cyclic silicate groups and silicon at the M4 site, according to the nomenclature of the eudialyte group.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 The characteristic feature of golyshevite is calcium-rich composition, with calcium at two main sites instead of one site.Chukanov, N.V., Moiseyev, M.M., Rastsvetayeva, R.K., Rozenberg, K.A., and Zadov, A.E., 2005. Golyshevite (Na,Ca)₁₀Ca₉(Fe³⁺,Fe²⁺)₂Zr₃NbSi₂₅O₇₂(CO₃)(OH)₃·H₂O, and Mogovidite, Na₉(Ca,Na)₆Ca₆(Fe³⁺,Fe²⁺)₂Zr₃[]Si₂₅O₇₂(CO₃)(OH,H₂O)₄, new eudialyte-group minerals from calcium-rich agpaitic pegmatites of the Kovdor massif, Kola Peninsula. Zapiski Rossiyskogo Mineralogicheskogo Obshchestva 134(6), 36-47 (in Russian, with English abstract) Together with feklichevite, fengchengite,

ikranite Ikranite is a member of the eudialyte group, named after the Shubinov Institute of Crystallography of the Russian Academy of Sciences. It is a cyclosilicate mineral that shows trigonal symmetry with the space group ''R''3''m'', and is often seen ...

and mogovidite it is a ferric-iron-dominant representative of the group. It is chemically similar to mogovidite. Golyshevite was named after Russian crystallographer Vladimir Mikhailovich Golyshev.

Occurrence and association

Golyshevite and mogovidite were found in

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...

-bearing peralkaline

pegmatite A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than and sometimes greater than . Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic com ...

s of the Kovdor massif, Kola Peninsula, Russia. Minerals associated with golyshevite are aegirine-

augite Augite is a common rock-forming pyroxene mineral with formula . The crystals are monoclinic and prismatic. Augite has two prominent cleavages, meeting at angles near 90 degrees. Characteristics Augite is a solid solution in the pyroxene group. ...

calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on ...

, cancrinite, hedenbergite, orthoclase, pectolite,

tacharanite Tacharanite is a calcium aluminium silicate hydrate (C-A-S-H) mineral of general chemical formula with some resemblance to the calcium silicate hydrate (C-S-H) mineral tobermorite. It is often found in mineral assemblage with zeolites and other ...

, and thomsonite-Ca.

Notes on chemistry

Impurities in golyshevite include

chlorine Chlorine is a chemical element with the Symbol (chemistry), symbol Cl and atomic number 17. The second-lightest of the halogens, it appears between fluorine and bromine in the periodic table and its properties are mostly intermediate betwee ...

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

cerium Cerium is a chemical element with the symbol Ce and atomic number 58. Cerium is a soft, ductile, and silvery-white metal that tarnishes when exposed to air. Cerium is the second element in the lanthanide series, and while it often shows the +3 o ...

and

lanthanum Lanthanum is a chemical element with the symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements between lantha ...

Notes on crystal structure

Calcium in golyshevite is present at M(1) and N(4) sites.

References

Cyclosilicates Sodium minerals Calcium minerals Iron(II,III) minerals Zirconium minerals Niobium minerals Trigonal minerals Minerals in space group 160 {{silicate-mineral-stub