naa a22 4500 510736246 CHVBK 20180411083011.0 cr unu---uuuuu 180411e20131201xx s 000 0 eng 10.1134/S1075701513070131 doi (NATIONALLICENCE)springer-10.1134/S1075701513070131 Aklimaite, Ca4[Si2O5(OH)2](OH)4 · 5H2O, a new natural hydrosilicate from Mount Lakargi, the Northern Caucasus, Russia [Elektronische Daten] [A. Zadov, I. Pekov, N. Zubkova, V. Gazeev, N. Chukanov, V. Yapaskurt, P. Kartasheov, E. Galuskin, I. Galuskina, N. Pertsev, A. Gurbanov, D. Pushcharovsky] A new mineral aklimaite, Ca4[Si2O5(OH)2](OH)4 · 5H2O, has been found near Mount Lakargi, Upper Chegem caldera, Kabardino-Balkaria, the Northern Caucasus, Russia, in the skarnified limestone xenolith in ignimbrite. This hydrothermal mineral occurs in a cavity of altered larnite skarn and is associated with larnite, calcium humite-group members, hydrogarnets, bultfonteinite, afwillite, and ettringite. Aklimaite forms transparent, colorless (or occasionally with pinkish tint) columnar or lath-shaped crystals up 3 × 0.1 × 0.01 mm in size, flattened on {001} and elongated along {010}; they are combined in spherulites. The luster is vitreous; the cleavage parallel to the {001} is perfect. D calc = 2.274 g/cm3. The Mohs' hardness is 3-4. Aklimaite is optically biaxial, negative, 2V meas > 70°, 2V calc = 78°, α = 1.548(2), β = 1.551(3), γ = 1.553(2). The IR and Raman spectra are given. The chemical composition (wt %, electron microprobe) is as follows: 0.06 Na2O, 0.02 K2O, 45.39 CaO, 0.01 MnO, 0.02 FeO, 24.23 SiO2, 0.04 SO3, 3.22 F, 27.40 H2O(calc.), −1.36 -O=F2; the total is 99.03. The empirical formula calculated on the basis of 2Si apfu with O + OH + F = 16 is as follows: (Ca4.02Na0.01)Σ4.03[Si2.00O5.07(OH)1.93][(OH)3.16F0.84] Σ4.00 · 5H2O. The mineral is monoclinic, space group C2/m, a = 16.907(5), b = 3.6528(8), c = 13.068(4) Å, β = 117.25(4)·, V= 717.5(4) Å3, Z = 2. Aklimaite is representative of the new structural type, the sorosilicate with disilicate groups [Si2O5(OH)2]. The strongest reflections in the X-ray powder patterns [d, Å (hkl)] are: 11.64(100)(001), 2.948(32)(310, 203), 3.073(20) ( $$\bar 404$$ , $$\bar 311$$ ), 2.320(12)(005, 510), 2.901 (11)(004), 8.30(10) $$\left( {\bar 201} \right)$$ . The type specimen is deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow. Pleiades Publishing, Ltd., 2013 Zadov A. NPP Teplokhim OOO, Dmitrovskoe sh. 100, Building 2, 127238, Moscow, Russia aut Pekov I. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut Zubkova N. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut Gazeev V. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut Chukanov N. Institute of Problem of Chemical Physics Russian Academy of Sciences, 142432, Chernogolovka, Moscow oblast, Russia aut Yapaskurt V. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut Kartasheov P. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut Galuskin E. Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, B dzun-ska 60, 41-200, Sosnowiec, Poland aut Galuskina I. Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, B dzun-ska 60, 41-200, Sosnowiec, Poland aut Pertsev N. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut Gurbanov A. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut Pushcharovsky D. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut Geology of Ore Deposits Springer US; http://www.springer-ny.com 55/7(2013-12-01), 541-548 1075-7015 55:7<541 2013 55 11477 https://doi.org/10.1134/S1075701513070131 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1075701513070131 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zadov A. NPP Teplokhim OOO, Dmitrovskoe sh. 100, Building 2, 127238, Moscow, Russia aut NATIONALLICENCE 700 1- Pekov I. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Zubkova N. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Gazeev V. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut NATIONALLICENCE 700 1- Chukanov N. Institute of Problem of Chemical Physics Russian Academy of Sciences, 142432, Chernogolovka, Moscow oblast, Russia aut NATIONALLICENCE 700 1- Yapaskurt V. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut NATIONALLICENCE 700 1- Kartasheov P. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut NATIONALLICENCE 700 1- Galuskin E. Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, B dzun-ska 60, 41-200, Sosnowiec, Poland aut NATIONALLICENCE 700 1- Galuskina I. Faculty of Earth Sciences, Department of Geochemistry, Mineralogy and Petrography, University of Silesia, B dzun-ska 60, 41-200, Sosnowiec, Poland aut NATIONALLICENCE 700 1- Pertsev N. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut NATIONALLICENCE 700 1- Gurbanov A. Institute of Geology of Ore Deposits, Petrography, Mineralogy, and Geochemistry, Russian Academy of Sciences, Staromonetnyi per. 35, 119017, Moscow, Russia aut NATIONALLICENCE 700 1- Pushcharovsky D. Faculty of Geology, Moscow State University, 119991, Moscow, Russia aut NATIONALLICENCE 773 0- Geology of Ore Deposits Springer US; http://www.springer-ny.com 55/7(2013-12-01), 541-548 1075-7015 55:7<541 2013 55 11477 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer