Interfacial electron transfer has been shown to occur between sorbed Fe(II) and structural Fe(III) in Fe oxides, but it is unknown whether a similar reaction occurs between sorbed Fe(II) and Fe(III)-bearing clay minerals. Here, we used the isotopic specificity of (57)Fe Mössbauer spectroscopy to demonstrate electron transfer between sorbed Fe(II) and structural Fe(III) in an Fe-bearing smectite...

It has long been recognized that the minerals in the clay (<2 gm) fractions of soils play a crucial role in determining their major physical and chemical properties, and inevitably, questions concerning the origin and formation of these minerals have assumed some prominence in soil science research. This review considers some important aspects of these questions and is confined to clay minerals...

High-resolution mapping by visible and near-infrared orbital spectrometers has revealed a diversity of hydrated mineral deposits on the surface of Mars. Quantitative analysis of mineral abundances within these deposits has the potential to distinguish depositional and diagenetic processes. Such analysis can also provide important constraints on the nature of putative global and local-scale mine...

This work examines the beneficial effects for human health of clay minerals, describing their use in pharmaceutical formulations, spas and aesthetic medicine. Their therapeutic action as active principles in pharmaceutical formulations orally administered (gastrointestinal protectors, laxatives, antidiarrhoeaics) or for topical applications (dermatological protectors and cosmetics) is described...

[1] To understand the role of hydrated clay minerals in active fault systems, a humidity chamber connected to an X-ray diffractometer was used to determine the adsorption of water onto and/or into the crystal structure of smectite. This new type of analysis was carried out under specific temperature and humidity conditions, using powdered clay size fractions (< 2 mm) of rock samples from the Sa...

An incubation experiment lasting 111 d was carried out to study the effect of the addition of three clay minerals (Nabentonite, Ca-bentonite, and zeolite) to soil derived from sewage sludge on water-extractable and exchangeable forms of four heavy metals (Zn, Cd, Cu, and Ni), as well as on soil organic matter mineralization, microbial biomass C and the release of inorganic N. The addition of cl...

The Main Glauconite Bed (MGB) is a pelleted greensand located at Stone City Bluff on the south bank of the Brazos River in Burleson County, Texas. It was deposited during the Middle Eocene regional transgression on the Texas Gulf Coastal Plain. Stratigraphically it lies in the upper Stone City Member, Crockett Formation, Claiborne Group. Its mineralogy and geochemistry were examined in detail, ...

Nitroaromatic compounds (NACs) are ubiquitous environmental contaminants that are susceptible to biological and abiotic reduction. Prior works have found that for the abiotic reduction of NACs, the logarithm of the NACs’ rate constants correlate with one-electron reduction potential values of the NACs (EH,NAC1) according to linear free energy relationships (LFERs). Here, we extend the applicati...

In this study, we focused on the presentation of clay minerals, their conditions formation and different categories. We also reported importance purification in removing impurities responses induced by heat treatment these minerals. Techniques used to detect minerals are exposed. On other hand, mineralogical, physicochemical thermal properties have a direct impact field use These differ from on...