Clay minerals have been used in medicinal applications since Aboriginal times (Carretaro, 2002; Wilson, 2003). Clay poultices are used to heal wounds; people eat clays to coat stomach linings and soothe indigestion; animals eat clay containing trace elements (e.g., As) that can kill worms. The reasons that various clay minerals are effective as medicines may be as variable as the ailment, but b...

[1] To understand the aqueous history of Mars, it is critical to constrain the alteration mineralogy of the Martian surface. Previously published analyses of thermal infrared (l = 6–25 mm) remote sensing data of Mars suggest that dark regions have 15–20% clay minerals. However, near-infrared (l = 1–3 mm) spectral results generally do not identify widespread clay minerals. Thermal infrared detec...

The desirable physical and physiochemical properties of clay minerals have led them to play a substantial role in pharmaceutical formulations. Clay minerals like kaolin, smectite and palygorskite-sepiolite are among the world's most valuable industrial minerals and of considerable importance. The elemental features of clay minerals which caused them to be used in pharmaceutical formulations are...

Chimpanzees of the Sonso community, Budongo Forest, Uganda were observed eating clay and drinking clay-water from waterholes. We show that clay, clay-rich water, and clay obtained with leaf sponges, provide a range of minerals in different concentrations. The presence of aluminium in the clay consumed indicates that it takes the form of kaolinite. We discuss the contribution of clay geophagy to...

The clay and non-clay minerals have been identified by XRD analysis. The non-clay minerals include quartz, crystobalite, orthoclase, microcline, plagioclase, calcite, siderite and dolomite, and the clay minerals include kaolinite (52.39%), illite (36.39%) and illite-smectite mixed layer minerals (11.21%). Kaolinite is the most dominant component in the clay mineral assemblages. The clay mineral...

Identification of clay minerals based on chemometric analysis of measured infrared (IR) spectra was suggested. IR spectra were collected using the diffuse reflection technique. Discriminant analysis and principal component analysis were used as chemometric methods. Four statistical models were created for separation and identification of clay minerals. More than 50 samples of various clay miner...

Besides having a large capacity for taking up organic molecules, clay minerals can catalyze a variety of organic reactions. Derived from rock weathering, clay minerals would have been abundant in the early Earth. As such, they might be expected to play a role in chemical evolution. The interactions of clay minerals with biopolymers, including RNA, have been the subject of many investigations. T...

Particles with nanometer dimensions (nanoparticles) are all around us. The finest particles of sand are blown by the wind over thousands of kilometers. The finest particles of soils are either eroded by the wind in extremely dry conditions or by water under wet conditions and deposited hundreds of kilometers or more from the origin. The air contains nanoparticles of carbon, ice, and oxides and ...

Mineral dust supplied to remote ocean regions stimulates phytoplankton growth through delivery of micronutrients, notably iron (Fe). Although attention is usually paid to Fe (hydr)oxides as major sources of available Fe, Fe-bearing clay minerals are typically the dominant phase in mineral dust. The mineralogy and chemistry of clay minerals in dust particles, however, are largely unknown. We con...

Expansive soils owe their characteristics to the presence of swelling clay minerals. As they get wet, the clay minerals absorb water molecules and expand; conversely, as they dry they shrink, leaving large voids in the soil. Swelling clays can control the behavior of virtually any type of soil if the percentage of clay is more than about 5 percent by weight. Soils with smectite clay minerals, s...