Oxide minerals origin

Of mineral origin inorganic chemistry is the study of all chemical elements and compounds, except carbon and its compounds certain simple carbon compounds, e.g., oxides and sulphides,... 

The crystal chemistry of many transition metal compounds, including several minerals, display unusual periodic features which can be elegantly explained by crystal field theory. These features relate to the sizes of cations, distortions of coordination sites and distributions of transition elements within the crystal structures. This chapter discusses interatomic distances in transition metal-bearing minerals, origins and consequences of distortions of cation coordination sites, and factors influencing site occupancies and cation ordering of transition metals in oxide and silicate structures, which include crystal field stabilization energies... 

Between the years 1400 and 1890 the reds that artists used were extracted from plants, such as madder, or from crushed insects, such as the scale insect Dactylopius coccus, or were of mineral origin, such as cinnabar (mercury sulfide, HgS) which could be ground to a powder to produce the pigment vermilion which was much used in antiquity, or red iron oxide (Fe203) which was used by the Neolithic cave painters, or minium (red lead, Pb304). 

Figure 7 Progressive stages of tnicrobially mediated iron oxide mineralization of a rod-shaped bacteria. Scale bars = 0.1 p,m (a) original bacteria, (b) early deposition of amorphous hydrated iron oxide (ferrihydrite), and (c) intense deposits of acicular magnetite (source Mann et al., 1992, photo 2, p. 118).

The success of the experiments documented above was primarily the result of the method used to prepare the Mn02 solid phase. By preparing a thin coating of the Mn02 mineral on a high surface area substrate (i.e. silt sized and smaller silica), it is possible to detect Mn reduction products in the presence of the original oxidized mineral. Because the redox reaction is surface mediated, too much of the... 

Reynolds R. L. and Goldhaber M. B. Origin of a South Texas roll-type uranium deposit 1. Alteration of iron—titanium oxide minerals. Econ. Geol., 73, 1978, 1677-89. 

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