 | | Journal (article/letter/editorial) | | Single-Crystalline Calcite Needle-Like Particles Using the Aragonite–Calcite Phase Transition Yuki Kezuka * ID ,...polymorphs: rhombohedral calcite and orthorhombic aragonite, the latter is thermodynamically metastable. In...In this study, we first prepared aragonite needle-like particles by introducing CO2 -containing gas into...resulted aragonite particles were heat treated at 500 ◦ C for 1 h, in order to induce the aragonite–calcite...carbonate has three crystalline polymorphs: calcite, aragonite and vaterite. Precipitation in aqueous systems |  | | Journal (article/letter/editorial) | | Graduate School of the City University of New York, Brooklyn, New York 11210 and Northeastern Science Foundation... 15 Third Street, P.O. Box 746, Troy, New York 12181-0746, USA AND D. J. SCHULTZ ARCO Oil & Gas Company...Company, 2300 West Piano Parkway, Piano, Texas 75075, USA Abstract Vaterite, a CaCO3 polymorph, is a rare...solution recrystallizes spontaneously to calcite or aragonite. Yet vaterite has been identified in hard tissues...in drilling fluids in wells of New York, Michigan, Nevada, Texas, and New Zealand. Petrographic examination |  | Toffolo, Michael, Regev, Lior, Dubernet, Stéphan, Lefrais, Yannick, Boaretto, Elisabetta (2019) FTIR-Based Crystallinity Assessment of Aragonite–Calcite Mixtures in Archaeological Lime Binders Altered by Diagenesis. Minerals, 9 (2) 121 doi:10.3390/min9020121 | Journal (article/letter/editorial) | | Article FTIR-Based Crystallinity Assessment of Aragonite–Calcite Mixtures in Archaeological Lime Binders...calcite and/or aragonite under different environmental settings. In nature, aragonite and calcite form...differences and assess the degree of atomic order of aragonite and calcite crystals and thus their mechanisms...short-range atomic order of a pyrogenic form of aragonite recently observed in experimental and archaeological...archaeological lime binders. We show that pyrogenic aragonite has a unique signature that allows its identification |  | | Journal (article/letter/editorial) | | California State University, Fullerton, CA 92834, USA Department of Stratigraphy and Palaeontology, Faculty...Dredgers, 1621 Westwood Avenue, Cincinnati, OH 45214, USA; E-Mail: billheim@cinci.rr.com Midwest Institute...Engineering, 2328 West Touhy Avenue, Chicago, IL 60645, USA; E-Mail: steveb@migeweb.org * Author to whom correspondence...preserve the earliest recorded nacre, we have examined new specimens of bivalves, gastropods, and cephalopods...purchased from Geological Enterprises (Ardmore, OK, USA). In total we examined via SEM 18 cephalopods, 25 |  | Cuif, Jean-Pierre, Dauphin, Yannicke, Nehrke, Gernot, Nouet, Julius, Perez-Huerta, Alberto (2012) Layered Growth and Crystallization in Calcareous Biominerals: Impact of Structural and Chemical Evidence on Two Major Concepts in Invertebrate Biomineralization Studies. Minerals, 2 (1) 11-39 doi:10.3390/min2010011 | Journal (article/letter/editorial) | | Alabama, 2018 Bevill Building, Tuscaloosa, AL 35487, USA; E-Mail: aphuerta@as.ua.edu * Author to whom correspondence...cells of the mineralizing tissues has revealed a new scale in complexity for these molecular assemblages...been greatly favored by a remarkable development of new physical methods allowing structural observations...are mostly built by crystal-like fibers (always aragonite in modern corals) generally arranged in variously...fibers viewed as “single crystals of orthorhombic aragonite”. Etching of polished surface of a fibrous fan-system |  | | Journal (article/letter/editorial) | | Copyright © 2000 Elsevier Science Ltd Printed in the USA. All rights reserved 0016-7037/00 $20.00 ⫹ .00 Pergamon...S0016-7037(00)00381-1 The role of vaterite and aragonite in the formation of pseudo-biogenic carbonate...reported. Vaterite formation occurs at ⬃25°C, aragonite at ⬃70°C and calcite at about ⬃80°C. These are...V/B.02–10) at 25°C, is least stable, whereas aragonite (orthorhombic, Pmcn, Dana class 14.1.3.1, Strunz...allowing stabilisation of the structure. Above 60°C aragonite was coordinated to nine oxygen atoms, possibly |  | | Report (chapter) | | service click here to receive free e-mail alerts when new articles cite this article Permission request click...non-skeletal marine precipitation (‘calcite’ and ‘aragonite seas’), has affected skeletal mineral secretion...the fossil record of marine organisms with an aragonite shell is widely depleted in some shelf settings...of molluscan lagerstätten from ‘calcite’ and ‘aragonite seas’ show a similar pattern of skeletal mineralogical...destruction of the less stable carbonate polymorphs, aragonite and high-Mg calcite, is increasingly recognized |  | | Journal (article/letter/editorial) | | http://www.tandfonline.com/loi/taje20 Origin of aragonite in a continental saline seep, north Queensland...article: E. N. Bui & A. R. Milnes (1994) Origin of aragonite in a continental saline seep, north Queensland...Earth Sciences (1994) 41, 497-503 Origin of aragonite in a continental saline seep, north Queensland...[Chulalongkorn University] at 02:34 10 January 2015 Aragonite, low-magnesian calcite, gypsum and halite were...seep and that of the carbonates, in particular aragonite, is probably due to a combination of evaporation |  | | Journal (article/letter/editorial) | | Santa Cruz, CA 95060, USA b USGS MS 910, 345 Middlefield Road, Menlo Park, CA 94025, USA c USGS MS 496, 345...345 Middlefield Road, Menlo Park, CA 94025, USA Received 20 November 2007; accepted in revised form 2 September...Because B, Ba and Sr occur exclusively in shell aragonite, they are good candidates for external proxy relationships...significantly different in prismatic and nacreous aragonite and in two valves of the same shell that had different...aragonitic and an inner layer composed of nacreous aragonite. The right and left valves of shells are unequally |  | Cuif, Jean-Pierre, Burghammer, Manfred, Chamard, Virginie, Dauphin, Yannicke, Godard, Pierre, Moullac, Gilles, Nehrke, Gernot, Perez-Huerta, Alberto (2014) Evidence of a Biological Control over Origin, Growth and End of the Calcite Prisms in the Shells of Pinctada margaritifera (Pelecypod, Pterioidea) Minerals, 4 (4) 815-834 doi:10.3390/min4040815 | Journal (article/letter/editorial) | | Alabama, 2018 Bevill Building, Tuscaloosa, AL 35487, USA; E-Mail: aphuerta@as.ua.edu * Author to whom correspondence...produce nacre, the “mother of pearls” composed of aragonite tablets. The scaly aspect of the external surface...the Pinctada longisquamosa (from Florida Keys, FL, USA). This appears to be the first mention of a structural...the line marking the onward progression of the aragonite mineralizing area (Figure 2b,c). On the other...the calcite and aragonite areas. Note the precise arrangement of the first aragonite patches onto the |  | | Journal (article/letter/editorial) | | Review of aragonite and calcite crystal morphogenesis in thermal spring systems Brian...cite this article as: Jones, Brian, Review of aragonite and calcite crystal morphogenesis in thermal spring... ACCEPTED MANUSCRIPT NU SC RI PT 1 Review of aragonite and calcite crystal morphogenesis in thermal spring...Jones@ualberta.ca ACCEPTED MANUSCRIPT 2 ABSTRACT Aragonite and calcite crystals are the fundamental building...the complexity of the factors that influence aragonite and calcite precipitation. Available information |  | | Journal (article/letter/editorial) | | Craniofacial Medicine, New York University, 345 E. 24th Street, New York, NY 10010, USA; jse1@nyu.edu; Tel...April 2017 Abstract: Over the last eight years new theories regarding nucleation, crystal growth, and...elements, such as the mollusk shell nacre layer (aragonite polymorph) and the sea urchin spicule (calcite...proteins, such as those from mollusk shell nacre aragonite, can promote polymorph formation. However, past...polymorphs; sea urchin; mollusk; calcite; vaterite; aragonite; biomineralization; proteins; classical nucleation |  | | Journal (article/letter/editorial) | | sequences and at their boundaries, Cenozoic, offshore New Jersey (ODP Leg 150): comment Received: 14 September...diagenesis in Cenozoic slope sequences of offshore New Jersey (U.S.) revisited our study sites of the 1960s...including the effect of methane on the slope of offshore New Jersey. As Vecsei and van der Smissen (1998) overlooked...and cemented by aragonite was recovered from this shelf at a depth of 79 m off the New Jersey coast (lat...School of the City University of New York, Brooklyn, NY 11210, USA Present address: Northeastern Science |  | Perdikouri, Christina, Kasioptas, Argyrios, Geisler, Thorsten, Schmidt, Burkhard C., Putnis, Andrew (2011) Experimental study of the aragonite to calcite transition in aqueous solution. Geochimica et Cosmochimica Acta, 75 (20) 6211-6224 doi:10.1016/j.gca.2011.07.045 | Journal (article/letter/editorial) | | elsevier.com/locate/gca Experimental study of the aragonite to calcite transition in aqueous solution Christina...2011 Abstract The experimental replacement of aragonite by calcite was studied under hydrothermal conditions...between 160 and 200 °C using single inorganic aragonite crystals as a starting material. The initial saturation...fracturing of the initial aragonite. The overall shape and morphology of the parent aragonite crystal were preserved...inherited from the oxygen isotope composition of the aragonite parent during the replacement process and is dependent |  | | Journal (article/letter/editorial) | | Copyright © 1999 Elsevier Science Ltd Printed in the USA. All rights reserved 0016-7037/21801 $20.00 1 .00...Pergamon PII S0016-7037(98)00299-3 Rates of aragonite conversion to calcite in dilute aqueous fluids...University of Minnesota, Minneapolis, MN 55455, USA (Received February 9, 1998; accepted in revised form...form September 24, 1998) Abstract—Aragonite was converted to calcite in dilute CaCl2 fluid at temperatures...temperatures ranging from 50 to 100°C. Surface areas of aragonite and calcite seed crystals were varied by over |  | | Journal (article/letter/editorial) | | Amsterdam - Printed in The Netherlands 169 [6] ARAGONITE DISSOLUTION ON THE BERMUDA PEDESTAL: ITS DEPTH...University, New Haven, Conn. (USA) ELIZABETH K. BERNER 15 Hickory Hill Road, North Haven, Conn. (USA) and ROBIN...Geology and Geophysics, Yale University, New Haven, Conn. (USA} Received October 30, 1975 Revised version...planktonic foram tests, and fine-grained (<62 tam) aragonite, high-Mg calcite (12 mode reel.% MgCOa), and low-Mg...pedestal. Over the range 1800-3000 m, fine-grained aragonite and fine-grained high-Mg calcite gradually disappear |  | | Journal (article/letter/editorial) | | waters. The bulk of the precipitate was CaCO3 in aragonite, as needles, and rhombohedral calcite crystals...basaltic formations in Iceland and northwestern USA (Alfredsson et al., 2008; Oelkers et al., 2008; ...decreases. The minerals observed are calcite and aragonite (both CaCO3), as well as brucite (Mg(OH)2) and...precipitates of the springs consist mainly of aragonite and calcite. The XRD patterns of the samples from...precipitate show rhombohedral calcite in a network of aragonite crystals (Figs 1a, 4a), whereas the precipitate |  | | Journal (article/letter/editorial) | | fabric may be indicative of either originally aragonite or calcite mineralogy. D 2005 Elsevier B.V. All...whereas most modern marine ooids are composed of aragonite, ancient ooids are typically calcitic. This discrepancy... to the conditions favoring precipitation of aragonite that are present today. Within the last twenty...cortices are composed of tangentially oriented aragonite needles, cortices of ancient ooids are typically...tangential aragonite to radial calcite. The basic premise of these workers is that bcalcitized aragonite consists |  | | Journal (article/letter/editorial) | | William and Mary, Gloucester Point, Virginia 23062, USA A. W. Droxler Department of Geology and Geophysics...Geophysics, Rice University, Houston, Texas 77251, USA man and Syvitski 1992). In contrast to fluvial sediments...carbonate sediments are primarily metastable aragonite and magnesian calcite; depending on the environment...shelf- and bank-derived magnesian calcite and aragonite, for example, might explain part of the alkalinity...of aragonite is as great as 3000 m; but near the Bahamas active export of bank-derived aragonite and |  | | Report (chapter) | | Earth history: a cooler-water phenomenon during aragonite-sea times? ANDREA C. K N O E R I C H & MARIA...(marine, marine burial and meteoric), whereas for aragonite sea shallow-water heterozoan carbonates generally...aragonitic components as an early cement source in aragonite-sea time non-tropical/heterozoan carbonates and...contrast, from the Upper Palaeogene until today (aragonite-sea time) the abundant occurrence of echinoderms...Comparison of the times of so-called 'calcite and aragonite seas' as described by Stanley & Hardie (1998) |  | | Journal (issue) | | Dr. Marian Lupulescu, Curator of Geology at the New York State Museum for more than twenty (20) years,...early 2010 during a visit to the New York State Museum in Albany, New York. We would cross paths several...researcher, and his scientific contributions to New York mineralogy were among the most thorough and precise...particularly his analytical work pertaining to New York State tourmalines and amphiboles. Marian authored...descriptions of the new minerals fluoropargasite and potassic-fluorohastingsite, both from New York, and he was |  | | Journal (article/letter/editorial) | | Geophysical Sciences, University of Chicago, Ill., 60637, USA Received 18 June 1973 The melting curves of CaCO3...magnesite are 1610°C and 1585 oC, respectively. New data for the magnesite dissociation reaction permit...vapor near 26 kb-1550 C. New data are also presented for the calcite-aragonite transition at 800°C, 950°C...calcite and aragonite was reacted with water for extension of the c a l c i t e aragonite transition curve...the reaction curves. No evidence was found for any new high-pressure polymorphs of CaCo3 or MgCO3, but the |  | | Journal (article/letter/editorial) | | skeletons and shells that are composed of either aragonite or calcite. Long-term changes in the estimated...connection between changes in the dominance of aragonite or calcite and the Mg/Ca ratio of the oceans,...eon has seen three episodes of aragonite-facilitating conditions (Aragonite I–III) and two episodes of ...these large-scale fluctuations that are known as aragonite and calcite seas12 . A Mg/Ca molar ratio of less...facilitates the precipitation of calcite, whereas aragonite is favoured under elevated Mg/Ca. Evidence is |  | | Journal (article/letter/editorial) | | 94305-2115, USA 4 Stanford Synchrotron Radiation Laboratory, SLAC, Menlo Park, California 94025, USA * e-mail:...within the thin layers of the stromatolites. Aragonite nanocrystals are also closely associated with...stromatolites, and extend the geologic record of primary aragonite by more than 2,300 Myr (ref. 6). We studied stromatolite...which are characterized by alternating layers of aragonite and an amorphous Mg–Si phase16 . Poorly ordered...unambiguously identify these crystallites as aragonite. Our nanoscale observations show that there are |  | | Journal (article/letter/editorial) | | NY 13244, USA Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA a r t i c...of Kentucky, USA. X-ray diffraction and scanning electron microscopy indicate an aragonite mineralogy with...detect, even with careful screening protocols. Aragonite, however, is much more likely to be primary because...While exceedingly rare in the Paleozoic record, aragonite has considerable potential to elucidate the significance...Stage Magoffin Shale, exposed in Hazard, Kentucky, USA. During the Pennsylvanian, the U.S. midcontinent |
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Tilly Foster Iron Mine, Town of Southeast, Putnam County, New York, USA