Terrestrial iron

E. Hussak, G. Florence, J. A. Antipoff, G. P. Merrill, W. Tassin, etc. H. E. Torne-bohm reported schreibersite in the terrestrial iron of Ovifak, although E. Cohen could not find it there G. vom Rath reported rhabdite in some pig-iron. A. Faye, E. Jannettaz, J. Gamier, and A. Daubree discussed the synthesis of these phosphides. E. Mallard identified the iron phosphide he obtained as the result of a coal-mine fire —vide supra—with rhabdite. G. Tschermak, J. L. Smith, E. Cohen, and E. Cohen and E. Weinschenk showed that dyslytite, schreibersite, and rhabdite are probably the same thing indeed, G. Tschermak found transition forms between acicular and foliated crystals—i.e. between schreibersite and rhabdite—in the meteorite of Braunau. 

Terrestrial iron was of course also used in Egypt. But iron manufacture was not well developed there. The Sinai Peninsula and the mountainous country of Nubia are considered to be suppliers of the desirable metal for the Egyptians. Even black Africa is pointed out as a supplier. Tutankhamun died in 1343 bc. The Iron Age was near, but the technical development did not occur in conservative Egypt. 

There is a general relationship between metal price and terrestrial concentration. Metals present at relatively high concentrations, in the earth s cmst, such as iron and aluminum, are the least expensive rare metals such as gold and platinum are the most valuable. This situation has existed for gold and silver valuation for centuries. The amount of silver in the earth s cmst is approximately 20 times that of gold, and the historical price ratio for gold and silver varied between 10 and 16 for over 3000 years. Since 1970 that price ratio has been strongly affected by market forces and investor speculation. 

Phosphorus is the eleventh element in order of abundance in crustal rocks of the earth and it occurs there to the extent of 1120 ppm (cf. H 1520 ppm, Mn 1060 ppm). All its known terrestrial minerals are orthophosphates though the reduced phosphide mineral schrieber-site (Fe,Ni)3P occurs in most iron meteorites. Some 200 crystalline phosphate minerals have been described, but by far the major amount of P occurs in a single mineral family, the apatites, and these are the only ones of industrial importance, the others being rare curiosities. Apatites (p. 523) have the idealized general formula 3Ca3(P04)2.CaX2, that is Caio(P04)6X2, and common members are fluorapatite Ca5(P04)3p, chloroapatite Ca5(P04)3Cl, and hydroxyapatite Ca5(P04)3(0H). In addition, there are vast deposits of amorphous phosphate rock, phosphorite, which approximates in composition to fluoroapatite. " These deposits are widely... 

Fig. 3.23 Left-. Calculated relationship between the thickness of an alteration rind and/or dust coating on a rock and the amount of 15.0-keV radiation absorbed in the rind/coating for densities of 0.4, 2.4, and 4.0 g cm [57]. The bulk chemical composition of basaltic rock was used in the calculations, and the 15.0 keV energy is approximately the energy of the 14.4 keV y-ray used in the Mossbauer experiment. The stippled area between densities of 2.4 and 4.0 g cm is the region for dry bulk densities of terrestrial andesitic and basaltic rocks [58]. The stippled area between densities of 0.1 and 0.4 g cm approximates the range of densities possible for Martian dust. The density of 0.1 g cm is the density of basaltic dust deposited by air fall in laboratory experiments [59]. Right Measured spectra obtained on layered laboratory samples and the corresponding simulated spectra, from top to bottom 14.4 keV measured (m) 14.4 keV simulated (s) 6.4 keV measured (m) and 6.4 keV simulated (s). All measurements were performed at room temperature. Zero velocity is referenced with respect to metallic iron foil. Simulation was performed using a Monte Carlo-based program (see [56])...

The largest category with a composition similar to terrestrial rocks oxygen, 36% iron, 26% silicon, 18% magnesium, 14% aluminium, 1.5% nickel, 1.4% calcium, 1.3%... 

Copper is part of several essential enzymes including tyrosinase (melanin production), dopamine beta-hydroxylase (catecholamine production), copper-zinc superoxide dismutase (free radical detoxification), and cytochrome oxidase and ceruloplasmin (iron conversion) (Aaseth and Norseth 1986). All terrestrial animals contain copper as a constituent of cytochrome c oxidase, monophenol oxidase, plasma monoamine oxidase, and copper protein complexes (Schroeder et al. 1966). Excess copper causes a variety of toxic effects, including altered permeability of cellular membranes. The primary target for free cupric ions in the cellular membranes are thiol groups that reduce cupric (Cu+2) to cuprous (Cu+1) upon simultaneous oxidation to disulfides in the membrane. Cuprous ions are reoxidized to Cu+2 in the presence of molecular oxygen molecular oxygen is thereby converted to the toxic superoxide radical O2, which induces lipoperoxidation (Aaseth and Norseth 1986). 

Terrestrial plants take up nickel from soil primarily via the roots (NRCC 1981 WHO 1991). The nickel uptake rate from soil is dependent on soil type, pH, humidity, organic content, and concentration of extractable nickel (NAS 1975 WHO 1991). For example, at soil pH less than 6.5 nickel uptake is enhanced due to breakdown of iron and manganese oxides that form stable complexes with nickel (Rencz and Shilts 1980). The exact chemical forms of nickel that are most readily accumulated from soil and water are unknown however, there is growing evidence that complexes of nickel with organic acids are the most favored (Kasprzak 1987). In addition to their uptake from the soils, plants consumed by humans may receive several milligrams of nickel per... 

Although arsenic is not an essential plant nutrient, small yield increases have sometimes been observed at low soil arsenic levels, especially for tolerant crops such as potatoes, com, rye, and wheat (Woolson 1975). Arsenic phytotoxicity of soils is reduced with increasing lime, organic matter, iron, zinc, and phosphates (NRCC 1978). In most soil systems, the chemistry of As becomes the chemistry of arsenate the estimated half-time of arsenic in soils is about 6.5 years, although losses of 60% in 3 years and 67% in 7 years have been reported (Woolson 1975). Additional research is warranted on the role of arsenic in crop production, and in nutrition, with special reference to essentiality for aquatic and terrestrial wildlife. 

Sandy M, Butler A. Microbial iron acquisition marine and terrestrial siderophores. Chem. Rev. 2009 109 4580-4595. 

Baur, M. E. (1978), "Thermodynamics of Heterogeneous Iron-Carbon Systems Implications for the Terrestrial Promotive Reducing Atmosphere", Chemical Geology 22,189-206. 

Figure 8. Figure (a) after Clayton et al. (1976, 1977). The scales are as in Figure 1. The O isotopic compositions of the different meteorite classes are represented ordinary chondrites (H, L, LL), enstatite chondrites (EFl, EL), differentiated meteorites (eucrites, lAB irons, SNCs) and some components of the carbonaceous chondrites. As the different areas do not overlap, a classification of the meteorites can be drawn based on O isotopes. Cr (b) and Mo (c) isotope compositions obtained by stepwise dissolution of the Cl carbonaceous chondrite Orgueil (Rotaru et al. 1992 Dauphas et al. 2002), are plotted as deviations relative to the terrestrial composition in 8 units. Isotopes are labeled according to their primary nucleosynthetic sources. ExpSi is for explosive Si burning and n-eq is for neutron-rich nuclear statistical equilibrium. The open squares represent a HNOj 4 N leachate at room temperature. The filled square correspond to the dissolution of the main silicate phase in a HCl-EIF mix. The M pattern for Mo in the silicates is similar to the s-process component found in micron-size SiC presolar grains as shown in Figure 7.

There are also indications that Ru displays systematic deficits in Ru in iron meteorites and in Allende relative to terrestrial composition (Chen et al. 2003). A deficit in s-process isotopes of Ru is the favored interpretation. 

Beard BL, Johnson CM (1999) High precision iron isotope measurements of terrestrial and lunar materials. Geochim Cosmochim Acta 63 1653-1660... 

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