Nontronite

The total amount of divalent cations in the octahedral sheet is considerably less than in the montmorillonites, and most octahedral sheets presumably have a net positive charge. In this respect the nontronites resemble the beidellites. Most of the 

Chemical analyses and structural formulas of some iron-bearing dioctahedral montmorillonites and nontronites 

Altschuler et al. (1963) marine clay associated with Bone Valley phosphates, Fla., U.S.A. analyzed by H. Kramer. 

Sawhney and Jackson (1958) soil developed on olivine basalt,-Waipiate, New Zealand analyzed by L.D. Swindalc. 

The analyses of dioctahedral smectites indicate that octahedral Fe and Al form a continuous isomorphous series and any subdivisions must be arbitrary. As the octahedral Al/Fe ratio increases, there is a tendency for octahedral Mg to increase (although 

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Transmission electron micrographs show hectorite and nontronite as elongated, lath-shaped units, whereas the other smectite clays appear more nearly equidimensional. A broken surface of smectite clays typically shows a "com flakes" or "oak leaf surface texture (54). High temperature minerals formed upon heating smectites vary considerably with the compositions of the clays. Spinels commonly appear at 800—1000°C, and dissolve at higher temperatures. Quartz, especially cristobalite, appears and mullite forms if the content of aluminum is adequate (38). 

Hydrothermal alteration minerals from midoceanic basalt are analcite, stilbite, heulandite, natrolite-mesolite-scolecite series, chlorite and smectite for zeolite facies, prehnite, chlorite, calcite and epidote for prehnite-pumpellyite facies, albite, actinolite, chlorite, epidote, quartz, sphene, hornblende, tremolite, talc, magnetite, and nontronite for green schist facies, hornblende, plagioclase, actinolite, leucoxene, quartz, chlorite, apatite, biotite, epidote, magnetite and sphene for amphibolite facies (Humphris and Thompson, 1978). 

Halmann and Aurian-Blajeni115 also examined C02 reduction by irradiation either with sunlight or a high-pressure Hg lamp of aqueous suspensions of various oxide semiconductors (i.e., Ti02, Fe203, W03, ZnO, and nontronite, an ion-containing clay mineral). 

Wang MC, Huang PM (1986) Humic macromolecular interlayering in nontronite through interaction with phenol monomers. Nature (London) 323 529-531 Wang MC, Huang PM (1988) Catalytic power of nontronite, kaolinite, and quartz and their reaction sites in the formation of hydroquinone-derived polymers. Appl Clay Sci 4 43-57... 

Fig. 2. Diagram showing the intercalation of compact quaternary ammonium cations, such as trimethylphenylammonium (TMPA) into different smectites, giving rise to type I organoclays with a basal spacing of about 1.5 nm. SWa is a high-charge nontronite (iron-rich smectite) and SAz is a high-charge montmorillonite, while SAC is a low-charge montmorillonite. After Jaynes and Boyd (1991b).

Nontoxic chlorofluorocarbons, 24 188 Nontronite (iron smectite), 6 664, 696 structure and composition, 6 669 Nonuniqueness, 24 446 Nonvessel operating common carriers (NVOCC), 25 328 Nonvolatile compounds, as taste substances, 11 566 Nonvolatile food components,... 

The palagonite is thermodynamically unstable and, hence, reacts with seawater to form various clay minerals, including smectites (montmorillonite, nontronite, and saponite), micas (celadonite), and zeolites (phillipsite). This chemical weathering involves uptake of Si, Al, Mg, Ca, Na, and K and the release of water, reversing to some extent, the elemental effect of palagonitization. These mineral alterations tend to proceed progressively from the outer margin of the pillow basalts to their interior. 

This makes the magnitude and direction of the eiementai fluxes difflcuit to generai-ize because of their dependence on such variabies as the water s temperature and circuiation rate and the rock s porosity and chemicai composition. Low-temperature weathering of basait is aiso accompanied by precipitation of iron oxides and iron uptake into various ciays (nontronite, saponite, and ceiadonite). 

Because of the relative scarcity of lithogenous particles and fast seafloor spreading rates, metalliferous sediments are common around the East Pacific Rise and very high densities of manganese nodules are present on the abyssal plains, especially in the Southern Hemisphere. In these locations, the weathering products of volcanic detritus, such as montmorillonite, phillipsite, nontronite, and celadonite, are also found in great abimdance. 

Komadel P, Madejova J, Stuck JW. 1995. Reduction and reoxidation of nontronite questions of reversibility. Clays and Clay Minerals 43 105-110. 

Fig. 1.5 The crystal structure of smectite, illustrating beidelite, montmorillonite and nontronite (Borchard 1989 after Brindley and MacEwan 1953)...

Organophosphate esters Hydrolysis Cu- and Mg-montmo-rillonite, Cu-BeideUite Cu-Nontronite Cu-mont. better catalyst than other Cu-clays or Mg-mont. 

In a further test of the clustering procedure, analyses of particles of standard clay minerals, ripidolite, montmorillonite, nontronite as well as muscovite mica, were clustered. The procedure easily identified the different minerals, giving rise to well... 

A quartz-free nontronite sample (6) was expanded by reacting a slurry containing 0.0075 g clay/g water with an excess of ChlorhydrolA pillared product was obtained that after drying at -100 C had a d(OOl) spacing of 19.4A. Calcination in air at 400 C/10h reduced the d(OOl) value to 16.9A the calcined ACH-Nontronite had BET surface area of 310 m /g and contained 31.9% FegOj. All powder diffraction measurements were obtained with a Siemens D-500 diffractometer at a scan of r/min using monochromatic Cu-Ka radiation. 

IR spectra for the pillared bentonites in the OH-stretching region show an intense and broad OH-band centered near 3640 cm this band is shifted to near 3600 cm for the ACH-nontronite sample under study, Fig. 1. After pyridine sorption, only minor changes were observed in these spectra, indicating little reaction of the hydroxyl groups present with pyridine. As the degassing temperature is increased from 200 C to 500 C, OH bands decrease in intensity due to dehydroxylation reactions of the clay lattice. Fig. 1. Dehydroxylation is more facile in the iron-containing ACH-nontronite sample. Fig. IF. 

ACH-nontronite sample seem to have initially a greater density of Bronsted... 

Fig. 1. Hydroxyl absorption bands for several smectites pillared with aluminum chlorhydroxide (ACH) soluctions A) Wyoming ACH-bentonite B) Texas ACH-bentonite C) Fe-bentonite D) ACH- Fe bentonite) E) (ACH, Fe)-bentonite and F) ACH-nontronite. Samples a) have been dried at 200 C and then loaded with pyridine and degassed at b) 200 C, c) 300 C, d) 400 C and e) 500 C in vacuo for 2 hours at each temperature.

ACH-Bentonite Wyoming from ISXM ACH- Nontronite (Fe,ACH)- Bentonite Crackin< Catalvsi... 

Special thanks are due to Mr. M. Bell, Dr. P. Ritz, and Dr. J. R. Glasmann (Unocal) for providing x-ray data, laser Raman measurements, and procedures for nontronite purification. S. L. Suib and M. L. Occelli acknowledge the Kinetics and Catalysis Division of the NSF for support of this work under grant CBT 8814974. 

Manceau, A., Chateigner, D., and Gates, W. P. (1998). Polarised EXAFS distance least squares valence modelling (DVLS) and quantitative texture analysis approaches to the structural refinement of Garfield nontronite. Phys. Chem. Miner. 25, 347-65. 

Figure 17. Proposed phase relations where K is a mobile component and Al, Fe are immobile components at about 20°C and several atmosphere water pressure for aluminous and ferric-ferrous mica-smectite minerals. Symbols are as follows I illite G = non-expanding glauconite Ox = iron oxide Kaol = kaolinlte Mo montmorillonite smectite N nontronitic smectite MLAL aluminous illite-smectite interlayered minerals Mlpe = iron-rich glauconite mica-smectite interlayered mineral. Dashed lines 1, 2, and 3 indicate the path three different starting materials might take during the process of glauconitization. The process involves increase of potassium content and the attainment of an iron-rich octahedral layer in a mica structure.

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