Phyllosilicate characterization

This chapter reviews recent work on the fabrication and characterization of bio-inorganic nanomaterials based on organically functionalized magnesium phyllosilicate materials. We begin with the general procedures used to synthesize and characterize these organodays (Section 8.2), and then describe how higher-order... 

Synthesis and Characterization of Organically Functionalized 2 1 Magnesium Phyllosilicates... 

Burkett, S.L., Press, A. and Mann, S. (1997) Synthesis, characterization and reactivity of layered inorganic-organic nanocomposites based on 2 1 trioctahedral phyllosilicates. Chemistry of Materials, 9, 1071—1073. 

Mineralogical interpretations of Halley dust analyses remain controversial. Lawler et al. (1989) saw no clustering of compositions that might suggest crystalline minerals (Fig. 12.5), whereas Fomenkova et al. (1992) identified compositions that were consistent with a number of minerals, including pyroxene, phyllosilicate, carbonate, FeNi metal, iron sulfide, and iron oxide. The characterization of minerals in returned comet dust (see below) supports the identification of some of these primary minerals but calls into question the identification of those formed by alteration. 

Asteroids that formed beyond the snowline represent rock and ice accreted inside the orbit of Jupiter. The most distant asteroids may still contain ices, but many asteroids have been heated. Melting of ice produced aqueous fluids, which reacted with chondritic minerals at low temperatures to form secondary minerals (phyllosilicates, carbonates, sulfates, oxides). The alteration minerals can be discerned in asteroid spectra and characterized by analyses of chondrites derived from these bodies. 

Fig. 2a shows a fault characterized by dense packing of grains only. In addition, most faults were enriched in phyllosilicates (see Fig. 2b), which probably is due to concentration of dispersed mica along the fault plane in an environment where meteoric water diagenesis occurred. Similarly, authigenic... 

Fig. 2. Photo-micrograph of fault structures from the Njord Field, Haltenbanken. (a) Micro-fault zone characterized by dense packing of grains only, (b) Micro-fault zone characterized by dense packing of grains and phyllosilicate enrichment. Dissolution of quartz occur at grain contact with mica (arrow), (c) Micro-fault zone with abundant stylolites.

Fig. 4. (a) Synsedimentary fault (sand dike) within the Etive Formation, Tampen Spur, (b) Early faults in the Etive Formation characterized by enrichment of phyllosilicates. Some of the faults are embedded by early carbonate cement (see text for further details). 

Mermut, A.R. 1994. Problems associated with layer charge characterization of 2 1 phyllosilicates. p. 105—122. In A.R. Mermut (ed.) Layer charge characteristics of 2 1 silicate clay minerals. Clay Miner. Soc., Boulder, CO. 

Forty years have passed since the first petrogenetic application of the illite structural changes for characterizing diagenetic processes in sedimentary basins (Weaver 1960). Weaver s sharpness ratio as well as Kibler s (1964, 1968) empirical illite crystallinity index, have been easy-to-use X-ray powder diffraction (XRD) measures of the manifold, inter-related changes that the hydrous, mica-like phyllosilicates experience during increasing burial. 

Bargar JR, Tebo BM, Villinski JE (2000) In situ characterization of Mn(II) oxidation by spores of the marine Bacillus sp. strain SG-1. Geochim Cosmochim Acta 64 2775-2778 Beauchemin D, Bednas ME, Berman SS, Sui KWM, Sturgeon RE (1988) Identification and quantification of arsenic species in a dogfish muscle reference material for trace elements. Anal Chem 60 2209-2212 Beaufort D, Baronnet A, Lanson B, Meunier A (1997) Corrensite A single phase or a mixed-layer phyllosilicate in the saponite-to-chlorite conversion series A case study of Sancerre-Couy deep drill hole (France). Am Mineral 82 109-124... 

Clay groups (phyllosilicates) in shale are characterized by different basal spacings in X-ray diffraction tests using glycerol-treated oriented clay specimens K=Kaolinite (7.2 A), I=Illite (9.9 A), C=Chlorite (14 A), V=Vermiculite (14.8 A), and S=Smectite (17 A) are the common families. 

Characterization of phase transitions (i.e., in rock-forming minerals such as feldspars, pyroxenes, phyllosilicates, etc.). 

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