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The x-ray identification and crystal structures of clay minerals
01 Jan 1961-
About: The article was published on 1961-01-01 and is currently open access. It has received 966 citations till now. The article focuses on the topics: Clay minerals.
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TL;DR: The Clay Minerals Society Source Clays project as discussed by the authors provides investigators with gently homogenized clay materials, carefully collected and processed under the supervision of clay specialists, with the introduction of the materials described in this paper.
Abstract: ### History
In any clay deposit, the nature of the mineral assemblage and the composition of individual clay minerals can change radically in a few cm. Consequently, any given locality can contain many subtly different types of clay minerals. Results from different laboratories on ostensibly the same clay material may not always be comparable because the samples may indeed not contain an assembly of identical clay minerals. Such confusion slows the understanding of this important group of minerals. Several attempts were made to provide investigators with reasonably constant clay materials, the first being that of the American Petroleum Institute Project 49 (Kerr, 1949). The Clay Minerals Society Source Clays project proposed to provide investigators with gently homogenized clay materials, carefully collected and processed under the supervision of clay specialists. The collection would include metric ton amounts to ensure a long-lasting collection. The program began in 1972, with the introduction of the materials described in this paper. Later the program expanded to include the Special Clays. These samples are materials not amenable to homogenization, or they are available in very small amounts.
Moll (1979) provided a full description and diagrams of geological occurrences and origins of the clay deposits. He also included details of collection and site maps. This paper updates the original work extensively by incorporating information obtained over the past two decades.
### Processing
The Baroid pilot plant in Houston, Texas processed most of the original samples. This processing was minimal, with drying on steam-fired tray driers at ≤100°C. Quartering techniques ensured an even feed into the pilot plant Raymond roller mill used for pulverization. Storage of the pulverized material was in large polyethylene bags in paperboard drums. The Southern Clay Products plant in Gonzales, Texas, processed the Texas white montmorillonite, using a rotary dryer and Raymond roller mill. Exhausted supplies of samples …
123 citations
TL;DR: In this article, the impact of three different clay minerals (montmorillonite, kaolinite and muscovite) on the dispersing force of vinyl-ether based superplasticizers was studied.
122 citations
TL;DR: The transformation of sodium and potassium smectite into mixed-layer clay was followed in hydrothermal kinetic experiments as mentioned in this paper, where glasses of beidellite composition and the Wyoming bentonite were used as starting materials.
Abstract: The transformation of sodium and potassium smectite into mixed-layer clay was followed in hydrothermal kinetic experiments. Glasses of beidellite composition and the Wyoming bentonite were used as starting materials. Temperatures ranged between 260 and 490°C at 2 kbar pressure, and run times ranged between 6 hr and 266 days. The course of the reactions was found to be strongly affected by interlayer chemistry. When potassium was the interlayer cation, increasing reaction produced the series: randomly interstratified illite/smectite-ordered interstratifled illite/smectite-illite. This sequence is equivalent to that formed in shales during burial diagenesis. With interlayer sodium and temperatures above 300°C, an aluminous beidellite (Black Jack analog)-rectorite-paragonite series was realized. The difference between these two diagenetic families is discussed. Below 300°C, sodium beidellite formed randomly interstratifled mixed-layer clay much like potassium beidellite, except that a higher layer charge was required to produce sodium mica-like layers. The higher charge resulted from sodium’s higher hydration energy. The difference in hydration energy between potassium and sodium may account for the fixation of potassium rather than sodium in illite during burial diagenesis. The appearance of ordered interlayering in mixed-layer phases is also related to interlayer chemistry. Ordering formed in sodium clays at high expandabilities, whereas it never appeared in the potassium clays above approximately 35% expandable. The appearance of ordering may be partly related to the polarizing power of the mica-like layers. Phase diagrams, constructed from the kinetic experiments and from the composition and occurrence of natural clays, are presented for the systems paragonite and muscovite-2 quartz-kaolinite-excess water. This study also reports the first synthesis of a Kalkberg-type mixed-layer clay.
118 citations
TL;DR: A range of authigenic sedimentary sedimentary chlorites from sandstones has been studied by analytical transmission electron microscopy as mentioned in this paper, and selected area (single crystal) electron diffraction patterns are of the Ib (fl = 90 ~ polytype confirming the earlier observations of Hayes (1970).
Abstract: A B S T R A C T. A range of authigenic sedimentary chlorites from sandstones has been studied by analytical transmission electron microscopy. Selected area (single crystal) electron diffraction patterns are of the Ib (fl = 90 ~ polytype confirming the earlier observations of Hayes (1970). TEM analyses show all samples to be relatively rich in both A1 and Fe. In the general formula (Mg,Fe,A1), [Sis_xAlxO20](OH)~6, x varies between 1.5 and 2.6; Fe/(Fe + Mg) between 0.47 and 0.83 and n between 10.80 and 11.54. Octahedral AI is close to 3 in this formulation and Fe 2§ predominates over Fe 3+. Swelling chlorites have significantly different compositions which are consistent with smectite/chlorite interstratifications. The Ib (fl = 90 ~ ) polytype appears to be stable under conditions of moderate to deep burial. It replaces berthierine and swelling chlorites formed at lower temperatures. As commonly seen in grain coatings, however, it precipitates from porewater; solutes probably being contributed from several mineral decomposition reactions.
117 citations
TL;DR: In this article, the authors proposed a method for the detection of organo-silicate complexes formed by ethylene glycol, HOCH2.CH2OH, and glycerol HOCH 2.CHOH.
Abstract: The complexes formed by ethylene glycol, HOCH2.CH2OH, and by glycerol, HOCH2.CHOH.CH2OH, with smectites (montmorillonite-saponite group), and vermiculites have received more attention than any other group of organo-silicate complexes. This interest arose in the first place from their use for identification purposes as proposed by MacEwan (1944, 1946) and by Bradley (1945b). Over the years, increasing attention has been given to the manner in which these complexes vary with the nature of the mineral, the magnitude and source of the charge on the silicate layers, and the number and kind of the exchangeable cations between the layers. The layer charge is determined most reliably from the full chemical analysis of a mineral, but more commonly is estimated from a measurement of cation exchange capacity.
114 citations