Pink Clay

Figure 11. Distribution with depth of U/Th normahzed to the bedroek in two lateritic profiles of the Kaya toposeqnenee, about 300m apart (Burkina Faso) (Deqnineey et al. 2002 submitted). One profile is located downhill (Kaya 5) and the other one at the top of a residual hill (Kaya 1). The laterite consists of an uppermost fermginous hardtop, an intermediate pink clay nnit and a lowest pistachio unit. For Kaya 5 profile, U/Th distribntion shows a relative enrichment of U in the nppermost horizon and depletion in the lower part of the profile. This kind of distribution is quite conunon in weathering profiles bnt is not systematic as illnstrated by the Kaya 1 profile. In the latter, a relative depletion of U is observed in the npper part and a U-enriched level in the intermediate horizon. This lateral difference in U distribution is explained by vertical redistribntion of U from the ferruginons top to the nnderlying horizons, whose intensity is controlled by the evolntion of the iron oxides from the nppermost horizons (Dequincey et al. snbmitted).

Pink Clay - a mixture of red and white clays. Used in facemasks for dry and sensitive skin. 

In-situ synthesis of the clay stabilized Au nanoparticles was also carried out by dissolving 1.68 g of MgCl2-6H20 (8.26 mmol) in 20 mL of 3.8 mM solution of HAuCL followed by the addition of 2 mL of 3-aminopropyltrimethoxysilane. The yellow slurry obtained was stirred overnight at room temperature and then kept at 75 °C for 24 h. It slowly turned pink in colour due to the formation of gold nanoparticles by thermal reduction. The pink transparent film obtained was washed with ethanol and then dried again. 

Fig. 2 shows how the aminoday -metal nanoparticle composites form clear transparent solutions in water. The solutions are pink and yellow for Au and Ag respectively and dark brown in the cases of both Pt and Pd. The reddish-brown colour observed for Au-clay nanoparticle composites immediately after the addition of NaBH4 changed to pink with time. The solutions exhibit characteristic piasmon bands for the Au- and Ag-day suspensions at 520 nm and 410 nm respectively as shown in Fig. 3. In the cases of Pt and Pd, the characteristic absorption band for the precursor s around 260 to 280 nm was absent thereby confirming the formation of Pt and Pd nanoparticles. 7,18 TEM images of the aminoday-metal nanoparticle composites deposited on a carbon coated copper grid are shown in Fig. 4. The histograms show the average particle sizes to be around 3.5 and 5 nm respectively in the cases of Au and Ag nanoparticles. We could see the layered arrangements in the cases of Pt and Pd with the interspacing of 1.5 nm commensurate with the bilayer arrangement of aminoclays (see top right inset of Fig. 4b).

PROP A clay containing appreciable amounts of the clay mineral montmoriUonite light yellow or green, cream, pink, gray to black soUd. Insol in water and common org solvs. 

Early diagenetic gypsum has a pyramidal (or hemi-bipyramidal) habit and grows displacively, commonly within siliciclastic sediment from interstitial porewater, and may be termed groundwater gypsum. Coalescing clusters or rosettes of this discoidal form (up to a few centimetres for each blade) lead to desert roses , some of which are indeed pink if clay or iron oxides are incorporated. 

Suppose an artisan wanted to coat a clay vessel with a faint pink glaze. What material should he or she add to a transparent glaze to achieve this result ... 

Rayner JH (1974) The crystal stracture of phlogopite by neutron diffraction. Mineral Mag 39 850-856 Reynolds RC, Thompson CH (1993) Illite from the Potsdam Sandstone of New York, a probable noncentrosymmetric mica stracture. Clays Clay Minerals 41 66-72 Richardson SM, Richardson JW (1982) Crystal stracture of a pink muscovite from Archer s Post, Kenya implications for reverse pleochroism in dioctahedral micas. Am Mineral 67 69-75 Rieder M, Cavazzini G, D yakonov YS, Frank-Kamenetskii VA, Gottardi G, Guggenheim S, Koval PV, Muller G, Neiva AMR, Radoslovich EW, Robert J-L, Sassi FP, Takeda H, Weiss Z, Wones DR (1998) Nomenclature of the micas. Clays Clay Minerals 46 586-595 Rieder M, Hybler J, Smrcok L, Weiss Z (1996) Refinement of the crystal structrrre of zirmwaldite 2Mi. Etrr J Mineral 8 1241-1248... 

Richardson SM (1976) Iron distribution in pink muscovite A reply. Am Mineral 61 1051-1052 Robbins DW, Strens RGJ (1972) Charge-transfer in ferromagnesian silicates The polarized electronic spectra of trioctahedral micas. Mineral Mag 38 551-563 Rolf RM, Kimball CW, Odom IE (1977) Mossbauer characteristics of Cambrian glauconite, central U.S. A. Clays Clay Minerals 25 131-137... 

Isolation of Product. Collect the orange-pink solid by vacuum filtration using a Hirsch funnel ( ). Wash the filter cake with four 1.0-mL portions of cold water from a calibrated Pasteur pipet. Maintain suction to aid in drying of the product. A piece of plastic food wrap over the mouth of the funnel can aid this process (see Prior Reading). Dry the material further on a porous clay plate, on filter paper, or under vacuum at room temperature. 

Stock Brick. Originally a term localized to S.E. England and meaning a clay building brick made by hand on a stock , i.e. the block of wood that defined the position of the mould on the moulding table. Stock bricks are now machine-made. The London Stock Brick is a yellow brick of rough texture. The term stock in the sense of usual , is sometimes applied to bricks of other areas, however, e.g. a Lincoln Stock is a semi-dry-pressed brick from the Lias. A Belfast Stock is a pink wire-cut brick from the Keuper Marl. 

Salter (1869) describes this as follows brown pink, brown Stil de Grain, citrine lake, or quercitron lake is usually prepared from the berries of Avignon (ramnus infectorius), better known as French, Persian, or Turkey berries but a more durable and quicker drying species is obtained from the quercitron bark... In eifrier case it is a lake, precipitated from the alkaline decoction by means of alum, in such proportions that the alkali shall not be more frian half saturated. The excess of soda or potash employed imparts a brown hue. Tingry (1804) describes a brown Dutch pink ( .v.) which has intense colour due to the use of pure clay as substrate. Heaton (1928) also lists brown pink, although as a pigment that is obsolete or of little importance at that time. 

The feldspar minerals have similar physical properties and often occur as prismatic or tabular crystals in igneous rocks, or as more anhedral grains in metamorphic and sedimentary rocks. They are colourless when fresh but are more commonly white due to incipient alteration impurities or inclusions result in coloured varieties, with green-brown alkali feldspars found in some metamorphic rocks, and orthoclase commonly found as pink. The surfaces of feldspar crystals are often iridescent due to twinning on a microscopic scale, with labradorite characterised by blue surface iridescence. Feldspars readily alter under hydrothermal action or chemical weathering to form members of the clay minerals group (. v.). Sodium-rich feldspars commonly decompose to form montmorillonite, in the presence of limited water, or to kaolinite with excess water alkali feldspars typically form illite or kaolinite sub-group (qq.v.) clay minerals (Deer et al, 1992 Rutley, 1988). 

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