Shkatulkalite, a Rare Mineral from the Lovozero Massif, Kola Peninsula: A Re-Investigation

Zolotarev, Andrey A.; Selivanova, Ekaterina A.; Krivovichev, Sergey V.; Savchenko, Ye. E.; Panikorovskii, Taras L.; Lyalina, L. М.; Pautov, Leonid A.; Yakovenchuk, Victor N.

doi:10.3390/min8070303

Cited by 7 publications

(2 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to their microporosity and catalytic activity, titanosilicates continue to attract considerable attention in the fields of materials science and nanochemistry (Rocha & Anderson, 2000;Noh et al, 2012;Milyutin et al, 2017;Oleksiienko et al, 2017;Přech, 2018;Cuko et al, 2018;Figueiredo et al, 2018). At the same time, they are of great interest from the viewpoint of mineralogy and geochemistry given their large diversity mostly in alkaline rocks such as those occurring in the alkaline massifs of the Kola peninsula, Russia, and Mont-Saint-Hilaire, Quebec, Canada (Cá mara et al, 2017;Selivanova et al, 2018;Zolotarev et al, 2018;Andrade et al, 2018;Lykova et al, 2018;Pakhomovsky et al, 2018;Pekov et al, 2019;Zhitova et al, 2019). Indeed, most titanosilicate materials used in industry were found as minerals before their unique properties were recognized.…”

Section: Introductionmentioning

confidence: 99%

Extraordinary structural complexity of ilmajokite: a multilevel hierarchical framework structure of natural origin

Zolotarev

Krivovichev

Cámara

et al. 2020

IUCrJ

View full text Add to dashboard Cite

The crystal structure of ilmajokite, a rare Na-K-Ba-Ce-titanosilicate from the Khibiny mountains, Kola peninsula, Russia, has been solved using single-crystal X-ray diffraction data. The crystal structure is based on a 3D titanosilicate framework consisting of trigonal prismatic titanosilicate (TPTS) clusters centered by Ce3+ in [9]-coordination. Four adjacent TPTS clusters are linked into four-membered rings within the (010) plane and connected via ribbons parallel to 101. The ribbons are organized into layers parallel to (010) and modulated along the a axis with a modulation wavelength of csinβ = 32.91 Å and an amplitude of ∼b/2 = 13.89 Å. The layers are linked by additional silicate tetrahedra. Na+, K+, Ba2+ and H2O groups occur in the framework cavities and have different occupancies and coordination environments. The crystal structure of ilmajokite can be separated into eight hierarchical levels: atoms, coordination polyhedra, TPTS clusters, rings, ribbons, layers, the framework and the whole structure. The information-based analysis allows estimation of the complexity of the structure as 8.468 bits per atom and 11990.129 bits per cell. According to this analysis, ilmajokite is the third-most complex mineral known to date after ewingite and morrisonite, and is the most complex mineral framework structure, comparable in complexity to paulingite-(Ca) (11 590.532 bits per cell).

show abstract

Section: Introductionmentioning

confidence: 99%

Extraordinary structural complexity of ilmajokite: a multilevel hierarchical framework structure of natural origin

Zolotarev

Krivovichev

Cámara

et al. 2020

IUCrJ

View full text Add to dashboard Cite

show abstract

“…The paper by Selivanova et al [16] reports on the compositional and textural variations in hainite-(Y) and batievaite-(Y), two rare-earth-containing minerals from the Sakharjok Massif, Keivy alkaline province (Eastern part of the Kola peninsula). Zolotarev et al [17] provides the first crystal-structure data on shkatulkalite, a rare mineral from the Lovozero massif that was discovered in 1996, but could not be structurally characterized until now.…”

mentioning

confidence: 99%

Editorial for Special Issue “Arctic Mineral Resources: Science and Technology”

Krivovichev

2019

Minerals

Self Cite

View full text Add to dashboard Cite

show abstract

Two Rinkite-Group (Seidozerite-Supergroup) Minerals: Nacareniobsite-(Y), a New Mineral from the Darai-Pioz Alkaline Massif, Tajikistan, and Crystal-Structure Refinement of Nacareniobsite-(Ce)

Agakhanov,

Day,

Sokolova

et al. 2023

The Canadian Journal of Mineralogy and Petrology

View full text Add to dashboard Cite

Nacareniobsite-(Y), ideally Na3Ca3YNb(Si2O7)2OF3, is a new rinkite-group (seidozerite-supergroup) TS-block mineral from the Darai-Pioz alkaline massif, Tien-Shan mountains, Tajikistan. The mineral is of hydrothermal origin. It occurs as prismatic crystals up to 1 mm long and 0.1 mm thick embedded in an aggregate of coarse-grained reedmergnerite. Associated minerals are reedmergnerite, leucophanite, nordite-(Ce), microcline, zeravshanite, polylithionite, kentbrooksite, yusupovite, fluornatropyrochlore, and quartz. Crystals are pale yellow, transparent, with a vitreous to translucent luster. Nacareniobsite-(Y) has a white streak, uneven to conchoidal fracture, and does not fluoresce under cathode or ultraviolet light. Cleavage is {100} very good, no parting was observed, Mohs hardness is 5, and it is brittle, Dmeas. = 3.49(2) g/cm3, Dcalc. = 3.515 g/cm3. It is biaxial (+) with refractive indices (λ = 590 nm) α = 1.662(2), β = 1.668(2), γ = 1.690(2); 2Vcalc. = 56°. It is nonpleochroic. Nacareniobsite-(Y) is monoclinic, space group P21/c, a = 7.4069(15), b = 5.6540(11), c = 18.787(4) Å, β = 101.36(3)°, V = 771.3(3) Å3. The six strongest reflections in the X-ray powder diffraction data [d(Å), I, (h k l)] are: 3.068, 100, (0 0 6, 1 2, 2 1 0); 2.944, 45, (2 1 1, 1 3); 2.707, 32, (0 2 2, 0 1 6); 5.44, 31, (0 1 1); 1.853, 29, ( 0 2, 2 1 7, 1 9); 3.59, 26, (1 0 4, 0 1 4). The empirical formula calculated on the basis of 18 (O + F) is Na2.82Ca3.06Sr0.14[Y0.37(Nd0.16Ce0.15Dy0.08Gd0.06Sm0.05La0.04Tb0.02Ho0.02Lu0.02Pr0.01Eu0.01Tm0.01Er0.01Yb0.01)Σ0.65]Σ1.02(Nb0.63Ti0.38)Σ1.01(Si4.00O14)O1.00F3.00, Z = 2. The ideal formula is Na3Ca3YNb(Si2O7)2OF3. The crystal structure was refined on a twinned crystal to R1 = 3.50% on the basis of 1788 unique reflections (Fo > 4σFo). It is a framework of TS (Titanium-Silicate) blocks where the TS block consists of HOH sheets (H = heteropolyhedral, O = octahedral) parallel to (100). In the O sheet, the Nb-dominant [6]MO(1) site is ideally occupied by one Nb apfu. The [8]MO(2) and [6]MO(3) sites are ideally occupied by one Na and two Na apfu, respectively. The H sheet contains two unique sites: the [7]MH site, ideally (CaY), is occupied by Ca1.23(Y0.37Ln0.40)Σ0.77, with <MH–φ> = 2.424 Å, and the [7]AP site, ideally Ca2, is occupied by Ca1.61Sr0.14Ln0.25, with <AP–φ> = 2.469 Å. The AP+ MH sites ideally give Ca2(CaY) apfu. The MH and AP polyhedra and Si2O7 groups constitute the H sheet. Linkages of the H and O sheets via common vertices of the MH and AP polyhedra, and Si2O7 groups with MO(1–3) polyhedra, results in the TS block. The TS block in nacareniobsite-(Y) exhibits linkage 1 and has a stereochemistry typical for the rinkite group (Ti + Nb + Zr = 1 apfu) of the seidozerite supergroup. For nacareniobsite-(Y), the ideal structural formula of the form AP2MH2MO4(Si2O7)2(XOM)2(XOA)2 is Ca2(CaY)Na3Nb(Si2O7)2(OF)F2. The mineral is named nacareniobsite-(Y), as it is structurally identical to nacareniobsite-(Ce), ideally Na3Ca3CeNb(Si2O7)2OF3, with Y as the dominant REE. The crystal structure of nacareniobsite-(Ce), has been refined to R1 = 6.80% for 1421 unique (Fo > 4σFo) reflections: space group P21/c, a = 7.4684(15), b = 5.6891(11), c = 18.891(4) Å, β = 101.37(3)°, V = 786.9(3) Å3, Z = 2, Dcalc. = 3.539 g/cm3. The composition of the MH and AP sites in the H sheet has been reassigned as follows: the [7]MH site is occupied by Ca1.28(Ln0.68Y0.04)Σ0.72 where Ce is the dominant lanthanoid, ideally (CaCe) apfu, <MH–φ> = 2.458 Å, and the [7]AP site is occupied by (Ca1.44Na0.09Sr0.04)Σ1.57Ln0.43, ideally Ca2apfu, <AP–φ> = 2.48 Å. The AP+ MH sites ideally give Ca2(CaCe) apfu [cf. (Ca,REE)2(Ca,REE)2apfu, Sokolova & Hawthorne (2008)]. For nacareniobsite-(Ce), the revised ideal structural formula of the form AP2MH2MO4(Si2O7)2(XOM)2(XOA)2 is Ca2(CaCe)Na3Nb(Si2O7)2(OF)F2.

show abstract

Shkatulkalite, a Rare Mineral from the Lovozero Massif, Kola Peninsula: A Re-Investigation

Cited by 7 publications

References 31 publications

Extraordinary structural complexity of ilmajokite: a multilevel hierarchical framework structure of natural origin

Extraordinary structural complexity of ilmajokite: a multilevel hierarchical framework structure of natural origin

Editorial for Special Issue “Arctic Mineral Resources: Science and Technology”

Two Rinkite-Group (Seidozerite-Supergroup) Minerals: Nacareniobsite-(Y), a New Mineral from the Darai-Pioz Alkaline Massif, Tajikistan, and Crystal-Structure Refinement of Nacareniobsite-(Ce)

Contact Info

Product

Resources

About