Spectra of minerals

Grey, I.E. Li, C. Watts, J.A. (1983) Hydrothermal synthesis of goethite-rutile intergrowth structures and their relationship to pseudorutile. Am. Min. 68 981-988 Griffith, W.P. (1974) Raman spectroscopy of minerals. In Farmer,V.C. (ed.) The infrared spectra of minerals. Min. Soc. London Monograph 4 119-136... 

Table 1.3. Luminescence centers found in steady-state spectra of minerals ...

Luminescence of was not confidently detected in steady-state luminescence spectra of minerals. In Ti minerals studiedby laser-induced time resolved... 

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. 

White W.B. (1974) The carbonate minerals. In The Infra-red Spectra of Minerals (ed. V.C. Farmer), pp. 227-284, Mineralogical Society of America Monograph 4, Mineralogical Society, London. 

Russell, J. D. In The Infrared Spectra of Minerals Farmer, V. C., Ed. Mineralogical Society Monograph 45 The Mineralogical Society London, 19745 PP 11-25. 

Optical Spectra. The optical properties of smectites have been studied by various workers (32,37-40), and involve several different types of electronic transitions. One important type of transition is the intervalence charge transfer (IT), which is observed in the optical spectra of minerals containing both Fe2 and Fe3 in their... 

The major focus of the book is on mineral crystal structures that provide an ordered array of anions forming coordination polyhedra around the central cations. The thermodynamic data underlying many of the geochemical applications described in the first ten chapters are derived from energies of absorption bands in the optical spectra of minerals, which are most simply explained by crystal field theory. Use of experimentally determined energy level data rather than energy separations computed in molecular orbital diagrams is the emphasis of these early chapters. 

The inverse fifth-power dependency of crystal field splitting on metal-oxygen distance expressed in eq. (2.17) is of fundamental importance in transition metal geochemistry, particularly in mineral physics at high pressures and interpretations of visible to near-infrared spectra of minerals. Thus, the A °= R 5 relationship, eq. (2.17), is referred to frequently in later chapters. 

Six types of spectra are theoretically possible in minerals of the orthorhombic, monoclinic and triclinic systems (McClure, 1959). However, for electric dipole transitions only three spectra are usually distinguished. These are the a, P and y spectra obtained when light is polarized along each of the three indicatrix axes, which in orthorhombic minerals such as olivine and orthopyroxene correspond to the three crystallographic axes. The majority of the spectra of minerals described in chapters 4 and 5 consist of polarized spectra measured in the three mutually perpendicular directions corresponding to a, P and y polarized light... 

Bums, R. G. (1985) Electronic spectra of minerals. In Chemical Bonding and... 

Measurements of electronic absorption spectra in the visible region not only lead to the evaluation of CFSE s, but they also provide useful information about the crystal chemistry of transition metal ions in the crystal structures and causes of colour and pleochroism of minerals. In this chapter, techniques for measuring absorption spectra of minerals are briefly described and some general applications of the optical spectra to basic crystal chemical properties, such as colour and pleochroism, are discussed. These examples also amplify many of the features of crystal field spectra outlined in chapter 3. 

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