Analytical techniques mineralogy

With the recent increased availability of Fourier transform spectrometers for routine laboratory use, there is great potential for infrared spectroscopy to become more widely used, both for the rapid identification of minerals and for more detailed structural studies. Despite being an established analytical technique, mineralogical infrared spectroscopy has been handicapped by a lack of high-quality reference spectra. There is currently no infrared equivalent of the JCPDS Mineral Powder Diffraction File and many new mineral descriptions still lack infrared spectra. Several compilations of mineral spectra are available but are far from comprehensive and are of variable reliability. Published mineral spectra are scattered throughout numerous journals and are often poorly reproduced with limited frequency ranges. 

Carbonates, organic matter, Fe and Mn oxides, and clay minerals play important roles in controlling overall reactivity of trace elements in soils and sediments. This chapter addresses the interaction of trace elements with carbonates, organic matter, Fe and Mn oxides and clay minerals. Analytical techniques for trace element speciation in solid-phase and their distribution among various solid-phase components in arid and semi-arid soils are reviewed. Solubilities of trace elements in solid phases and their mineralogical characteristics in arid and semi-arid soils also are discussed. 

ABSTRACT The aim of this study was to test portable infrared spectroscopy for non-destructive analysis of ancient construction mortar. Mortar samples from the House of the Vestals, in Pompeii, Italy, were initially examined with traditional analytical techniques, including X-ray fluorescence, X-ray diffraction and thin section analysis. These techniques were used to establish mineralogical and chemical profiles of the samples and to verify the results of experimental field methods. Results showed the lime-based binder was composed of calcite, and the volcanic sand aggregate contained clinopyroxene, plagioclase, sanidine and olivine crystals. 

Chemical elements that are either present naturally in the soil or introduced by pollution are more usefully estimated in terms of availability of the element, because this property can be related to mobility and uptake by plants. A good estimation of availability can be achieved by measuring the concentration of the element in soil pore water. Recent achievements in analytical techniques allowed to expand the range of interest to trace elements, which play a crucial role both in contaminated and uncontaminated soils and include those defined as potentially toxic elements (PTE) in environmental studies. A complete chemical analysis of soil pore water represents a powerful diagnostic tool for the interpretation of many soil chemical phenomena relating to soil fertility, mineralogy and environmental fate. This chapter describes some of the current methodologies... 

Trace element compositions and mineralogy of the soils and Penobscot Formation were obtained by various analytical techniques including XRD, XRF, ICP-MS, and INAA. Table 12.4 is a summary of the trace element data for the leach aliquots obtained on the soils in the Pb isotope study, and for the Penobscot Formation. 

Spectroscopic measurement is a particularly favored analytical technique because spectra can be compared in a direct way to interpret the chemical and mineralogical composition of dust in various astronomical environments. Depending upon the different spectral regions under analysis and depending on the optical properties of the material, one must use different techniques. In regions of strong absorption, such as in the phonon band range (mid-infrared) or the ultraviolet, direct absorption measurements require very low column densities of material, which can only be achieved with thin films or diluted powder samples. 

The study of chondrite matrices is both time-consuming and challenging, principally because of the fine-grained characteristics of the material. Transmission electron microscopy (TEM) has been the analytical technique of choice, because it provides textural and mineralogical information from the micron down to the nanoscale. Here, we briefly overview the main textural and mineralogical characteristics of matrices in very un-equilibrated chondrites, focusing principally on the carbonaceous chondrites. 

The effects of the mineral matter depend on the chemical and mineralogical composition. Many standard analytical techniques are available to quantify the elements present in the mineral species. These include silicon, aluminum, iron, calcium, magnesium, sodium, potassium, titanium and others. The elements are usually reported as oxides, because the oxide anion is the predominant one in fly ash. However, the mineral species are not usually simple oxides, but very frequently are tied up in the different mineral forms as more complex aluminosilicates or other species as indicated above. A variety of techniques is used to identify the mineral matter. 

Thermogravimetric analytical techniques A group of thermal analytical techniques in which the change in mass of a sample undergoing incremental heating is used to identify the mineralogical composition. 

The research of Edgar Fahs Smith and his students at the University of Pennsylvania represents an attempt to bring electrolysis into standard analytical practice and to revolutionize mineralogy. From 1890 until 1910, Smith and his students developed two new electrolytic analytical techniques, the rotating anode and the double-cup mercury cathode that gave a simpler and faster electrolysis with a more complete separation. Smith and his students published a total of twenty-six papers exploring the uses of these techniques, which Smith further promoted through his widely-used textbook. Electrochemical Analysis. (1-2)... 

After considerations about the health-related properties of inhaled particles and their fate in the lung, this chapter will examine the role and usefulness of mineralogical analysis studies, the sampling and analytical techniques, the methodological limitations and the interpretation of the results. 

Often phase identification is not enough and it is desirable to quantitatively determine the amounts of the different components within a sample. Examples of applications where this may be useful might include monitoring of product quality, modeling of mineralogy with process conditions, or determination of crystalline components that have significant effects on the property of the materials such as cordierite in kiln furniture. X-ray diffraction is inherently less quantitative than other analytical techniques such as X-ray fluorescence, but with careful use of standards, calibration, or processes such as standard addition, reasonably good results can be obtained. 

Raman spectroscopy, while typically used as a micro-analytical tool, can be conducted remotely. Performance of remote Raman analysis have been recently explored and reahzed for experiments on the surface of Mars (Sharma et al. 2001 Sharma et al. 2003). Raman spectroscopy is a powerful technique for mineralogical analysis, where the sharpness of spectral features of minerals allows for much less ambiguous detection, especially in the presence of mixtures. Visible, near-infrared, thermal, reflectance and in many cases emission spectroscopy of minerals all suffer from broad overlapping spectral features, which complicates interpretation of their spectra. On the other hand, Raman spectra of minerals exhibit sharp and largely non-overlapping features that are much more easily identified and assigned to various mineral species. 

The Swiss Agency of Environment and Landscape decided to re-evaluate mechanical metal separation techniques to reduce the landfill volume and to improve the BA quality for deposition by exploiting metal resources. A sampling campaign in all 28 incineration plants was initiated to verify BA quality and to establish a solid data base. A common sampling procedure, sample treatment, and analytical method were prescribed in order to obtain consistent information of chemical and structural composition and the leaching behaviour of current BA. This paper is focused on the chemical and mineralogi-cal results from the study. 

These thin-film techniques, which usually entail a small, focussed electron beam ( 20-50nm diameter) and an EDS detector for the measurement of secondary X-rays, have been applied to many mineralogical problems with considerable success. Many areas of geology and mineralogy, both terrestrial and extraterrestrial, can benefit from the analytical power of the modern-day AEM because the fundamental relationships between microchemistry and bulk physical properties can be effectively explored. 

Most primary condensates are extremely small, ranging from 5 nm to 50 nm in diameter. Adequate characterization of such grains must rely on very high spatial resolution techniques such as transmission electron microscopy (TEM) or analytical electron microscopy (AEM). In the former technique, the emphasis is on obtaining very clear pictures of the morphology, homogeneity, elemental and mineralogical... 

An interesting development of analytical electron microscopy, and a potentially very useful one for mineralogical research, has been made by Spence and Tafto (1982,1983). The technique, known as ALCHEMI (atom location by channeling enhanced microanalysis), is the electron analogue of an x-ray technique originally used by Batterman (1969). The theoretical basis of the technique was discussed in Chapter 4, but it is appropriate to summarize that discussion before considering the ALCHEMI technique in detail. 

This chapter examines the compositions, mineralogy, sources, and geochemical significance of IDPs. Additional reading can be found in reviews by Fraundorf (1981), Brownlee (1985), Sandford (1987), Bradley etal. (1988), Jessberger et al. (2(X)1), Rietmeijer (1998), and the book edited by Zolensky et al. (1994). Despite their micrometer-scale dimensions and nanogram masses it is now possible, primarily as a result of advances in small particle handling techniques and analytical instrumentation, to examine IDPs at... 

This chapter has presented detailed information on the more common analytical instrumentation and preparation procedures used in chemical and mineralogical analysis, and an overview of selected microanalytical techniques that still require development in this field. It must be emphasised that the quality of results and the information that can be obtained... 

Electrochemical methods can also be used for obtaining analytical information on porous materials. Voltammetric methods and related techniques have been largely used to acquire information on reaction mechanisms for species in solution phase, whereas impedance techniques have been extensively used in corrosion and metal surface studies. In the past decades, the scope of available methods has been increased by the development of the voltammetry of microparticles (Scholz et al., 1989a,b). This methodology, conceived as the recording of the voltammetric response of a solid material mechanically transferred to the surface of an inert electrode, provides information on the chemical composition, mineralogical composition, and speciation of solids (Scholz and Lange, 1992 Scholz and Meyer, 1994, 1998 ... 

Metal oxide and hydroxide systems serve many functions, including roles as pigments, in mineralogy, and also in catalysis. The classic techniques used in such investigations have included diffraction (especially X-ray diffraction XRD), thermal analysis, transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy (see also Chapters 2 and 4). Until the introduction of voltammetry in the analysis of immobilized microparticles, electrochemical studies had been confined to solid electrolyte cells (Chapter 12), normally functioning at elevated temperatures. Unfortunately, these studies proved to be inapplicable for analytical characterization, and consequently a series of systematic studies was undertaken using immobilized microparticles of iron oxides and oxide-hydrates (for reviews, see... 

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