Mineralogical material analysis

With a combined VIS + NIR SI system and a fuzzy-C-means classification algorithm, it was possible to set up a fast, compact, contact-less and non-destructive analytical instrument. As shown in Fig. 7.7, the two-range spectroscopic imager is capable of distinguishing among true turquoises, even if they are set into bedrock (b), treated turquoises (pressed turquoise powder, etc.), synthetic turquoises and nonturquoise materials without sample pre-treatment with high reliability.18 

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Published references cannot substitute for personal examination of the raw materials and all raw feed components are subjects for microscopical analysis. For our purposes, the important data in raw materials analysis are mineralogy, microstructure, and chemistry. 

Bearat, H., M. Fuchs, M. Maggetti, and D. Paunier (eds.) (1997), Roman Wall Paintings Materials, Techniques, Analysis and Conservation, Institute of Mineralogy and Petrography, Fribourg Univ., Fribourg, Switzerland. 

Two different approaches have been taken by researchers to determine the secondary mineralogy of CCBs (1) direct observation, which is accomplished via analysis of weathered ash materials, and (2) prediction, based on chemical equilibrium solubility calculations for ash pore-waters and/or experimental ash leachate or extractant solutions. Because the secondary phases are typically present in very low abundance, their characterization by direct analysis is difficult. On the other hand, predictions based on chemical equilibrium modelling or laboratory leaching experiments may not be reliable indicators of element leachability or accurately indicate the secondary phases that will form under field conditions (Eighmy et al. 1994 Janssen-Jurkovicova et al. 1994). 

Eh and pH at which the process takes place. In both cases the role of organic material is evident and similar, acting as a motor in changing the aspect of the silicate in the pellet both in chemistry and mineralogy from that of the enclosing sediment. The reasons for the development of one mineral species or the other are at the moment somewhat obscure but, considering the similarity of the occurrence, the mechanism is probably the same. With this in mind the analysis which follows for sedimentary glauconites can be considered applicable for sedimentary 7 X chlorite pellets. 

Problems relating to measurement and interpretation of the hardness of brittle materials are still awaiting suitable analysis and assessment, to give valid evaluation of the results of measurements often carried out by methods very different from the technique applied to the tested material. This idea has served as the basis of this book. It is addressed primarily to industrial laboratory workers and theoretical research workers who are trained at academic level. The material it contains also qualifies it as a practical training textbook for students of mineralogy, solid body physics and materials engineering. 

The successful application of thin-film techniques to the solution of mineralogical problems depends, in part, upon the nature of instrumentation used and also upon the level of precision required for (a) chemical data and (b) the spatial resolution of the analysis. Each of these matters will be described in some detail below whilst utilising examples from the mineral and the materials sciences. 

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