Roxley Iron Clays (200 Count)

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The FT of the EXAFS spectra of the low Fe-loading anoxic samples equilibrated at pH ∼8, showed a second peak at ∼2.75 Å (uncorrected for phase shift). This second shell was fitted with Fe located at a radial distance of 3.15–3.17 Å and a coordination number of 1.8–2.1. The fitted distance for the second shell corresponds with an intermediate distance of edge-sharing Fe atoms around Fe( II) and Fe( III) as in fougerite 56 and lepidocrocite, 64 respectively. This is consistent with the results obtained by LCF and Mössbauer spectroscopy.

A. P. Zhukhlistov, Crystal structure of lepidocrocite FeO(OH) from the electron-diffractometry data, Crystallogr. Rep., 2001, 46, 730–733 CrossRef . These sit in sleek plastic storage trays, with an ornate decorated box. These have shelf presence galore, when you’re not playing with them! And talking of which, you shouldn’t feel restricted to only using these Iron Clays for use with Brass. They function as excellent components for any tabletop game, or poker night. D. G. Rancourt and J. Y. Ping, Voigt-based methods for arbitrary-shape static hyperfine parameter distributions in mossbauer-spectroscopy, Nucl. Instrum. Methods Phys. Res., Sect. B, 1991, 58, 85–97 CrossRef . A. Neumann, T. B. Hofstetter, M. Skarpeli-Liati and R. P. Schwarzenbach, Reduction of polychlorinated ethanes and carbon tetrachloride by structural Fe(II) in smectites, Environ. Sci. Technol., 2009, 43, 4082–4089 CrossRef CAS PubMed . If you love luxury in board games, then you’re going to fall in love with these Iron Clays! Many board games come with punchboards, providing cardboard coin chits. They work from a functional point of view. But nothing quite compares to premium components, does it? There are gaming counters, and then there’s the next-level goodies. That’s where these Iron Clays come into their own…I am a board game player. I am also now the self-appointed family curator of a fairly decent sized collection of games. When budget allows for new cardboard recruits, my default is to seek out a new full game. Sometimes it flexes to admit an expansion to a beloved shelf-veteran. But when I saw the Iron Clays, all rules went out of the window. They went straight onto our shared Christmas wish list! Iron Maidens a b c d Bailey SW (1980). "Summary of recommendations of AIPEA nomenclature committee on clay minerals". Am. Mineral. 65: 1–7. See also: Pottery Hexagonal sheets of the clay mineral kaolinite ( SEM image, 1,340× magnification) A lower amount of lepidocrocite was formed in the low Fe-load samples, as direct oxidation of Fe 2+ in presence of elevated Si concentrations (high Si/Fe ratio in solution) may mainly precipitate as ferrihydrite. 73 However, only a small fraction of the sorbed Fe in the oxic samples was formed by direct oxidation of dissolved Fe 2+ for low Fe-loading samples equilibrated at pH ∼8 (between 7 and 12%, see Fig. S4 and S5 †) compared to samples equilibrated at pH ∼7 (between 60 and 65%, see Fig. S4 and S5 †). Nevertheless both low Fe-loading samples resulted in the presence of similar solid phases. The higher fraction of lepidocrocite observed in the high Fe-loading oxic samples as compared to the low Fe-loading samples may be due to the oxidation of dissolved Fe 2+ in the presence of a low Si/Fe ratio in solutions, which favors lepidocrocite formation over ferrihydrite or through the transformation of green rust into lepidocrocite. 66,73 Because only a small fraction of the sorbed Fe (up to 20%, see Fig. S4 and S5 †) was formed by direct oxidation of dissolved Fe 2+ in high Fe-loading samples, lepidocrocite was primarily formed from the transformation of Fe-phases precipitated under anoxic conditions. D. Soltermann, M. Marques Fernandes, B. Baeyens, J. Miehé-Brendlé and R. Dähn, Competitive Fe(II)–Zn(II) uptake on a synthetic montmorillonite, Environ. Sci. Technol., 2014, 48, 190–198 CrossRef CAS PubMed .

J. Jonsson and D. M. Sherman, Sorption of As(III) and As(V) to siderite, green rust (fougerite) and magnetite: Implications for arsenic release in anoxic groundwaters, Chem. Geol., 2008, 255, 173–181 CrossRef CAS . Clay minerals can be classified as 1:1 or 2:1. A 1:1 clay would consist of one tetrahedral sheet and one octahedral sheet, and examples would be kaolinite and serpentinite. A 2:1 clay consists of an octahedral sheet sandwiched between two tetrahedral sheets, and examples are talc, vermiculite, and montmorillonite. The layers in 1:1 clays are uncharged and are bonded by hydrogen bonds between layers, but 2:1 layers have a net negative charge and may be bonded together either by individual cations (such as potassium in illite or sodium or calcium in smectites) or by positively charged octahedral sheets (as in chlorites). [9] with smectites: Temporal changes in redox reactivity and the formation of green rust, Environ. Sci. Technol., 2017, 51, 12573–12582 CrossRef CAS PubMed . J. Klausen, S. P. Trober, S. B. Haderlein and R. P. Schwarzenbach, Reduction of substituted nitrobenzenes by Fe(II) in aqueous mineral suspensions, Environ. Sci. Technol., 1995, 29, 2396–2404 CrossRef CAS PubMed . R. Dähn, A. M. Scheidegger, A. Manceau, M. L. Schlegel, B. Baeyens, M. H. Bradbury and M. Morales, Neoformation of Ni phyllosilicate upon Ni uptake on montmorillonite: A kinetics study by powder and polarized extended X-ray absorption fine structure spectroscopy, Geochim. Cosmochim. Acta, 2002, 66, 2335–2347 CrossRef .

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C. A. Gorski, M. Aeschbacher, D. Soltermann, A. Voegelin, B. Baeyens, M. Marques Fernandes, T. B. Hofstetter and M. Sander, Redox properties of structural Fe in clay minerals. 1. Electrochemical quantification of electron-donating and -accepting capacities of smectites, Environ. Sci. Technol., 2012, 46, 9360–9368 CrossRef CAS PubMed . Fig. 2 Derivative of normalized Fe K-edge XANES spectra of Fe 2+ sorption samples in which Syn-1 (∼5 g L −1) was reacted with low (0.25 mM) or high (2.5 mM) Fe 2+ concentrations at pH ∼7 or ∼8. Sorption samples were equilibrated for 1 day under anoxic conditions (green lines) and subsequently oxidized for 1 day (orange lines). Superscripts (a–d) indicate the corresponding pairs of anoxic and oxidized samples. Displayed pH values correspond to the pH measured at the end of the equilibration period for each sample. Selected reference spectra of solid phases containing Fe( II) and/or Fe( III) are shown for comparison (abbreviations: Nk = nikischerite, Cl-GR = chloride green rust, Fh = ferrihydrite). Environmental significance Clay minerals are considered major sorbents in soils and sediments. However, their significance for the redox cycling of iron is still unclear. Under anoxic conditions, elevated concentrations of dissolved ferrous iron are observed. We demonstrate that at circumneutral to alkaline pH, surface-mediated oxidation of ferrous iron can occur under anoxic conditions in the presence of clays that are virtually free of structural iron. The retention of dissolved ferrous iron in the presence of clay minerals was evidenced to be mainly due to the formation of secondary Fe( II/ III) phases. Subsequent aeration led to the complete oxidation of iron. In contrast to surface precipitation, adsorption of dissolved iron by layered aluminosilicates plays a minor role in iron retention and does not protect ferrous iron from oxidation. W. L. Lindsay and A. P. Schwab, The chemistry of iron in soils and its availability to plants, J. Plant Nutr., 1982, 5, 821–840 CrossRef CAS . X. W. Xu, C. Chen, P. Wang, R. Kretzschmar and F. J. Zhao, Control of arsenic mobilization in paddy soils by manganese and iron oxides, Environ. Pollut., 2017, 231, 37–47 CrossRef CAS PubMed .

For exclusively board game players Iron Clays are a no brainer and I would probably tell you to buy them without hesitation… J. W. Gruner, The composition and structure of minnesotaite, a common iron silicare in iron formations, Am. Mineral., 1944, 29, 363–372 CAS . P. Refait, L. Simon and J. M. R. Genin, Reduction of SeO 4 2- anions and anoxic formation of iron(II)-iron(III) hydroxy selenate green rust, Environ. Sci. Technol., 2000, 34, 819–825 CrossRef CAS . A. Manceau, Critical evaluation of the revised akdalaite model for ferrihydrite, Am. Mineral., 2011, 96, 521–533 CrossRef CAS .Hartman, Hyman (1998). "Photosynthesis and the Origin of Life". Origins of Life and Evolution of Biospheres. 28 (4–6): 515–521. Bibcode: 1998OLEB...28..515H. doi: 10.1023/A:1006548904157. PMID 11536891. S2CID 2464. A. M. Scheidegger, G. M. Lamble and D. L. Sparks, Spectroscopic evidence for the formation of mixed-cation hydroxide phases upon metal sorption on clays and aluminum oxides, J. Colloid Interface Sci., 1997, 186, 118–128 CrossRef CAS PubMed . Wall M (12 March 2013). "Mars Could Once Have Supported Life: What You Need to Know". Space.com . Retrieved 12 March 2013. C. Mikutta, X-ray absorption spectroscopy study on the effect of hydroxybenzoic acids on the formation and structure of ferrihydrite, Geochim. Cosmochim. Acta, 2011, 75, 5122–5139 CrossRef CAS . Fig. 4 LCF fitting results of Fe K-edge EXAFS spectra of Fe 2+ sorption samples equilibrated for 1 day under anoxic conditions (green lines) and subsequently oxidized for 1 day (orange lines) and relevant references: (a and b) absolute fractions of Fe references obtained by linear combination fitting of k 3-weighted Fe K-edge EXAFS spectra for Fe 2+ sorbed on Syn-1. High Fe load (a and c) and low (b and c) (0.25 mM) sorption samples. The fits were performed over a k-range of 2–11.3 Å −1 ( k w = 3) with no fit constraints. The initial fit fractions (70.9–146.2%) were normalized to the sum equal to 100% and are reported in Tables S11 and S12 † (abbreviations: Nk = nikischerite, Cl-GR = chloride green rust, Lp = lepidocrocite, Fh = ferrihydrite). (c) k 3-weighted χ spectra of references (line): SWy-2, Fe(OH) 2, nikischerite, chloride green rust, ferrihydrite and lepidocrocite are shown together with the k 3-weighted χ spectra (open circles) of 1 day equilibrated samples with corresponding fit (green and orange colors correspond to anoxic and oxidized samples, respectively). Displayed pH values correspond to the pH measured at the end of the equilibration period for each sample. Superscripts (a–d) indicate the corresponding pairs of anoxic and oxidized samples.