Elements Goldschmidt classification

Table A.4. Geochemical classification of the elements (after Goldschmidt )...

Geochemical subdivision of the Periodic Table. The Goldschmidt s geochemical classification of the elements in the Periodic Table is presented in Fig. 4.10... 

Goldschmidt (32) also introduced the concept of a geochemical classification of elements, in which the elements are classified on the basis of their affinities and tendencies to occur in minerals of a single group. The chalcophile elements are those which commonly form sulfides. In addition to sulfur, they include Zn, Cd, Hg, Cu, Pb, As, Sb, Se, and others. When present in coals, these elements would be expected to occur, at least in part, in sulfide minerals. Sulfides other than pyrite and marcasite have been noted in coals, but, except in areas of local concentration, they occur in trace or minor amounts. 

A rather different approach to understanding the condensation of the solar nebula came from the work of the geochemist V.M. Goldschmidt carried out in the 1920s. Goldschmidt proposed, what has now become, a widely used geochemical classification of the elements. This work was in part based upon the study of meteorites, and so his classification is very relevant to the understanding of planetary processes. 

However, Goldschmidt s scheme only relates to the condensation of major elements into mineral phases. As the solar nebula hypothesis gained credence, it became clear that there are other element groupings which relate to the condensation of a high-temperature solar gas. These are the refractory elements - those which formed above the condensation temperature of the Mg silicates and Fe-Ni metal, at 1,300-1,400 K, the moderately volatile elements - those formed in the range 1,300-670 K, and the volatile elements - those that formed below the condensation temperature of FeS, at 670 K (Larimer, 1988). Palme and O Neill (2003) have proposed a cosmochemical/geo-chemical classification of the elements based on these two elemental groupings (Table 2.1). 

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