 | | Journal (article/letter/editorial) | | from Shiowakka, TOSHIHIKO Laboratory of Earth Science, Hokkaido University of natural ikaite Japan...Hokkaido 085-8580, Japan (Received July 16, 1997; Accepted March 17, 1998) Ikaite (CaC03.6H20) transforms...of water promotes the transformation of natural ikaite to calcite in a room but the presence of magnesium...concentration in a solution which contacts with ikaite, being analogous to those on the formation of calcium...calcium bicarbonate solution. Rapid transformation of ikaite is favorable to the formation of vaterite, a metastable |  | | Journal (article/letter/editorial) | | PII S0016-7037(00)00620-7 Seasonal formation of ikaite (CaCO3 䡠 6H2O) in saline spring discharge at Expedition...thermally unstable crystals believed to be the mineral ikaite (CaCO3 䡠 6H2O) growing seasonally along two spring...has hampered attempts to confirm the presence of ikaite by X-ray diffraction. However, various field observations...surroundings, and attempts to determine the validity of ikaite precipitation at this site by theoretical geochemical...are compared with other reported observations of ikaite to both understand their occurrence and help delineate |  | Sánchez-Pastor, N., Oehlerich, Markus, Astilleros, José Manuel, Kaliwoda, Melanie, Mayr, Christoph C., Fernández-Díaz, Lurdes, Schmahl, Wolfgang W. (2016) Crystallization of ikaite and its pseudomorphic transformation into calcite: Raman spectroscopy evidence. Geochimica et Cosmochimica Acta, 175. 271-281 doi:10.1016/j.gca.2015.12.006 | Journal (article/letter/editorial) | | Accepted Manuscript Crystallization of ikaite and its pseudomorphic transformation into calcite: Raman...Fernández-Díaz, L., Schmahl, W.W., Crystallization of ikaite and its pseudomorphic transformation into calcite:...apply to the journal pertain. Crystallization of ikaite and its pseudomorphic transformation into calcite:...schmahl@lrz.unimuenchen.de (W. W. Schmahl). Abstract Ikaite (CaCO3·6H2O) is a metastable phase that crystallizes...of the original ikaite crystal is preserved as a pseudomorph. Pseudomorphs after ikaite are considered |  | Tang, C. C., Thompson, S. P., Parker, J. E., Lennie, A. R., Azough, F., Kato, K. (2009) The ikaite-to-vaterite transformation: new evidence from diffraction and imaging. Journal of Applied Crystallography, 42 (2). 225-233 doi:10.1107/s0021889809005810 | Journal (article/letter/editorial) | | papers Journal of Applied Crystallography The ikaite-to-vaterite transformation: new evidence from diffraction...dSPring-8/JASRI, 1-1-1 Kouto, Mikazuki-cho, Sayo-gun, Hyogo 679-5198, Japan. Correspondence e-mail: c.c.tang@diamond...the formation of vaterite from decomposition of ikaite (CaCO36H2O) was investigated using synchrotron...of the precursor ikaite (0.5–1.0 mm) as a result of vaterite nucleating as ikaite dehydrates. The rate...arrangement of the hydration sphere around Ca2+ in ikaite determines the orientation of Ca2+ and CO32 ions |  | | Journal (article/letter/editorial) | | and Synthesis of Glendonites (Pseudomorphs after Ikaite) with New Data: Assessing Applicability as Recorders...AND SYNTHESIS OF GLENDONITES (PSEUDOMORPHS AFTER IKAITE) WITH NEW DATA: ASSESSING APPLICABILITY AS RECORDERS...colgate.edu ABSTRACT: Calcite pseudomorphs after ikaite (glendonite) are associated with coldwater depositional...dictated by the limited stability field of ikaite. Ikaite precipitation is favored by elevated alkalinity...oxidation is occurring. The rapid recrystallization of ikaite to calcite during slight warming or pressure release |  | | Journal (article/letter/editorial) | | 2014 Structural change induced by dehydration in ikaite (CaCO3·6H2O) Natsuki TATENO and Atsushi KYONO Division...Tsukuba, Ibaraki 305–8572, Japan Dehydration–induced structural change in ikaite, CaCO3·6H2O, is investigated...diffraction study. At −50 °C, the crystal structure of ikaite is monoclinic, of space group C2/c with the unit...anisotropically along the a–axis followed by the c–axis. The ikaite structure is finally lost at 0 °C, which is a much...elongated immediately before the decomposition of ikaite structure. These expansions along the b–axis, however |  | | Journal (article/letter/editorial) | | aqueous Mg2+/Ca2+ ratio on the (trans-)formation of ikaite B. Purgstaller a,⇑, M. Dietzel a, A. Baldermann...Abstract The calcium carbonate hexahydrate mineral ikaite (CaCO3 s_ 6 H2O) has been documented in aquatic...environment, results in the transformation of natural ikaite into less soluble calcium carbonate phases occasionally...understanding on the physicochemical parameters controlling ikaite (trans-)formation however, such as temperature...under debate. In order to study the formation of ikaite, we conducted precipitation experiments under controlled |  | | Journal (article/letter/editorial) | | The petrology of ikaite pseudomorphs and their diagenesis J. M. Huggett", B. P. Schultz", 'n, J. Shearman"...Petrographic examination of pseudomorphs after ikaite (CaCO".6H 2 0 ) from five localities around the...all samples examined suggests that the initial ikaite decomposition followed a similar pattern in all...Denmark). Gennoishi (pseudomorphs from the Miocene, Japan) and jarrowites (pseudomorphs from Quaternary muds...Tyne, UK) contain only type I calcite. Key words: ikaite, gcnnoishi, harnmerstone, jarrowite, thinolite |  | | Journal (article/letter/editorial) | | minerals Article Calcium Carbonate Hexahydrate (Ikaite): History of Mineral Formation as Recorded by Stable...G.; Müller, P.J. Calcium Carbonate Hexahydrate (Ikaite): History of Mineral Formation as Recorded by Stable...Deceased. Abstract: Calcium carbonate hexahydrate (ikaite) is a rare mineral that forms as metastable species...fluids and dissolved gases of the host sediment. The ikaite crystal faithfully records in its zonal structure...isotope fractionation. The oxygen isotopes of the ikaite carbonate (δ18 Oikaite = 1.46 to 4.45‰) also show |  | | Journal (article/letter/editorial) | | University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan b Graduate School of Science, The University of...Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan c Institute of Nature and Environmental Technology...University, Kakuma, Kanazawa, Ishikawa 920-1192, Japan Received 15 March 2012; accepted in revised form...lakes, the presence of MHC has been reported as ikaite tufa debris in the seawater environment of the...2006) and in the saline cold waters of Shiowakka Spring in Japan (Ito, 1993). MHC has been reported as |  | Field, L. P., Milodowski, A. E., Shaw, R. P., Stevens, L. A., Hall, M. R., Kilpatrick, A., Gunn, J., Kemp, S. J., Ellis, M. A. (2017) Unusual morphologies and the occurrence of pseudomorphs after ikaite (CaCO3·6H2O) in fast growing, hyperalkaline speleothems. Mineralogical Magazine, 81 (3) 565-589 doi:10.1180/minmag.2016.080.111 | Journal (article/letter/editorial) | | morphologies and the occurrence of pseudomorphs after ikaite (CaCO3·6H2O) in fast growing, hyperalkaline speleothems...the ‘cold climate’ calcium carbonate polymorph, ikaite (calcium carbonate hexahydrate: CaCO3·6H2O), with...previously published crystallization temperatures for ikaite (<6°C). Analysis of a stalagmite actively growing...vessel, indicates that following crystallization of ikaite, decomposition to calcite occurs rapidly, if not...polymorph observed within speleothems. K E Y WO R D S : ikaite, speleothem, hyperalkaline, calcium carbonate hexahydrate |  | | Journal (article/letter/editorial) | | c h e m g e o Calcium isotope fractionation in ikaite and vaterite Nikolaus Gussone a,⁎, Gernot Nehrke...April 2011 Editor: J.D. Blum Keywords: Vaterite Ikaite Calcium carbonate polymorph Calcium isotopes a...metastable calcium carbonate polymorphs vaterite and ikaite. The synthetic vaterite precipitates show a smaller...significant temperature sensitivity between 10 and 50 °C. Ikaite, the water-bearing Ca carbonate modification (CaCO3·6H2O)...values of Ca isotope fractionation. In general, ikaite is less depleted in heavy isotopes compared to |  | | Journal (article/letter/editorial) | | from transformation of a metastable phase such as ikaite (CaCO3·6 H2O). A gradual decrease of conductivity...modeling suggests that, in addition to calcite and ikaite, silica, clay minerals, ferrihydrite, gibbsite...phases. Additional thermodynamic data were added for ikaite (Bischoff et al., 1993a), allophane and imogolite...analyzed samples (Fig. 2); no vaterite, aragonite or ikaite were visible. Mismatch of sample 140 J. Olsson...edges of the metastable hydrated CaCO3 phase called ikaite, that transformed into fine grained calcite. with |  | | Journal (article/letter/editorial) | | by modeling the hydrous calcium carbonate phase ikaite, which is a crystalline calcium carbonate hexahydrate...aqueous calcium and carbonate ions (DG = –37 kJ/mol), ikaite is less stable than the anhydrous form calcite...parameters of ikaite (de Leeuw and Parker 1997), and a change in enthalpy for the dissocation of ikaite into calcite...R.J. (1993) The solubility and stabilization of ikaite (CaCO3·6H2O) from 0 rC to 25 rC—environmental and...controlling the transformation of natural ikaite from Shiowakka, Japan. Geochemical Journal, 32, 267–273. Katz |  | Rodriguez-Blanco, Juan Diego, Shaw, Samuel, Bots, Pieter, Roncal-Herrero, Teresa, Benning, Liane G. (2014) The role of Mg in the crystallization of monohydrocalcite. Geochimica et Cosmochimica Acta, 127. 204-220 doi:10.1016/j.gca.2013.11.034 | Journal (article/letter/editorial) | | hydrated phases monohydrocalcite (CaCO3H2O) and ikaite (CaCO36H2O). Monohydrocalcite forms in a variety...successfully applied to other hydrated carbonates like ikaite, which is even scarcer in nature and more unstable...from calcareous sinter of cold spring of Shiowakka, Asyoro. J. Mineral. Petrol. Econ. Geol. 88, 485–491...Lennie A., Wellner J. and Anderson J. B. (2012) An ikaite record of late Holocene climate at the Antarctic...H., Zabel M. and Lennie A. (2006) Potential of ikaite to record the evolution of oceanic d18O. Geology |  | | Journal (article/letter/editorial) | | metastable polymorphs vaterite, monohydrocalcite, and ikaite have been documented in a wide range of precipitation...Israelson C., Seaman P. and Stockmann G. (2001) Ikaite Tufa Towers in Ikka Fjord, Southwest Greenland:...from calcareous sinter of cold spring of Shiowakka, Asyoro. J. Mineral. Petrol. Econ. Geol. 88, 485–491...Lennie A., Wellner J. and Anderson J. B. (2012) An ikaite record of late Holocene climate at the Antarctic |  | | Journal (article/letter/editorial) | | and several hydrated forms (monohydrocalcite and ikaite). The ⇑ Correponding author. Tel.: +34 91 3944876...been related to the formation of hydrated CaCO3 ikaite (CaCO36H2O) (Larsen, 1994) in natural environments...119, 505–511. Ito T. (1996) Ikaite from cold spring water at Shiowakka, Japan. J. Min. Pet. Econ. Geol....Paleoenvironmental Significance of calcite pseudomorphs after ikaite in the Oligocene Creede Formation. Colorado. J |  | | Journal (article/letter/editorial) | | thermodynamically more stable than ikaite (CaCO3)(H2O)6 (de Leeuw and Parker, 2001). Since ikaite is a potential precursor...controlling the transformation of natural ikaite from Shiowakka, Japan. Geochem. J. 32, 267–273. 86 Y. Yang...evolution of Ca–Mg–Fe carbonates in some coalfields of Japan. Sedimentology 28, 239–259. Meot-Ner M. (1988) Ionic |
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