Ivanyukite-Na-T, ivanyukite-Na-C, ivanyukite-K, and ivanyukite-Cu: New microporous titanosilicates from the Khibiny massif (Kola Peninsula, Russia) and crystal structure of ivanyukite-Na-T

Crystal chemistry of ivanyukite-group minerals, A3–xH1+x[Ti4O4(SiO4)3](H2O)n (A = Na, K, Cu), (n = 6–9, x = 0–2): crystal structures, ion-exchange, chemical evolution

“…In nature, these minerals occur in natrolitised microcline–aegirine–sodalite veins within an orthoclase-bearing urtite of the Koashva apatite mine (Fig. 1), Khibiny alkaline massif, Kola Peninsula, Russia (Yakovenchuk et al , 2009). They are found in a hyperagpaitic low-temperature hydrothermal assemblage in association with natrolite, villiaumite, sitinakite, djerfisherite, sazykinaite-(Y), lucasite-(Ce), and amorphous bitumens.…”

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

“…The ion-exchanger UOP-910, which is used for the removal of Cs-137 from radioactive-waste solutions (Anthony et al, 1994), is a natural counterpart of sitinakite, a microporous titanosilicate from hydrothermal veins of the Khibiny massif, Kola peninsula, Russia (Sokolova et al, 1989;Men'shikov et al, 1992). Another family of recently described microporous titanosilicates, the ivanyukite-group minerals (Yakovenchuk et al, 2009), have the pharmacosiderite-type structure, well known as a useful synthetic material since the 1990s (Harrison et al, 1995). There are many other unique natural titanosilicates with interesting structures that have no precedents among synthetic materials.…”

Titanite Ores of the Khibiny Apatite-Nepheline-Deposits: Selective Mining, Processing and Application for Titanosilicate Synthesis

“…In addition to titanite and titanomagnetite, the apatite-nepheline deposits contain numerous pegmatites with rare titanium minerals that have important functional properties, for example, ferroelectric loparite-(Ce) [2], molecular sieve chivruaiite [3,4] (Ca-analog of synthetic microporous titanosilicate ETS-4 [5,6]), cation exchangers kukisvumite and punkaruaivite [7][8][9][10] (respectively, Zn and Li analogues of synthetic titanosilicate AM-4 [11,12]), cation exchangers sitinakite [13] (natural analogue of synthetic titanosilicate Ionsiv IE-911 [14][15][16]), and minerals of the ivanyukite group [17][18][19][20]. Besides, these and other synthetic titanium-based compounds (ETS-2, ETS-10, JDF-L1, LHT-9, MIL-125, etc.)…”

“…Moreover, ( 137 Cs, 90 Sr, 154 Eu)-exchanged forms of ivanyukite can be transformed by heating into stable SYNROC-like titanate ceramics for long-time immobilization of these radionuclides [20]. Crystal structure of ivanyukite-Na-T [17]: cubano-like clusters Ti4O24 consisting of four edgeshared TiO6 octahedra (dark-blue) are connected by vertexes SiO4 tetrahedra (yellow) to form the microporous framework, with Na (cyan), K (pale green), and H2O (magenta) in channels.…”

“…Crystal structure of ivanyukite-Na-T[17]: cubano-like clusters Ti 4 O 24 consisting of four edge-shared TiO 6 octahedra (dark-blue) are connected by vertexes SiO 4 tetrahedra (yellow) to form the microporous framework, with Na (cyan), K (pale green), and H 2 O (magenta) in channels.…”