Iron native

The earliest record of human usage of iron dates to ca 2000 BC (5) in Egypt, Asia Minor, Assyria, China, and India. It is almost certain, however, that the first iron to be used was not processed but was obtained from meteorites (1). One of the few places where native iron is found is in Greenland, where it occurs as very small grains or nodules in basalt (an iron-bearing igneous rock) that empted through beds of coal. 

Bird, J. N. and M. S. Weathers (1977), Native iron occurrence in Dikko Island, Greenland, J. Geol. 85, 359-371. 

The nickel proteins and the native iron globins show the same behavior in regard to fifth-ligand photodissociation but for totally different reasons. Heme proteins and other metal-reconstituted heme proteins have been investigated by transient absorption spectroscopy (49-53) and transient Raman spectroscopy (16,54-62). In none of the Fe proteins is loss of the histidine ligand observed even on a picosecond timescale. Soret excitation of carbonmonoxy and oxy Hb and Mb photolyzes CO or O2, but not the histidine fifth ligand. 

Nickel in Meteorites. Centuries before the discovery of nickel, primitive peoples shaped meteoric iron into implements and swords and appreciated the superiority of this Heaven-sent metal (125). In 1777 J. K. F. Meyer of Stettin noticed that when he added sulfuric acid to some native iron which P. S. Pallas had found in Siberia, he obtained a green solution which became blue when it was treated with ammonium hydroxide. In 1799 Joseph-Louis Proust detected nickel in meteoric iron from Peru (126). This grayish white native iron had been observed by Rubin de Celis. Since it did not rust, it was sometimes mistaken for native silver. 

Led by the deep green color of its solutions to suspect the presence in it of copper, Proust passed hydrogen sulfide into an acidic solution of tire iron, but obtained no precipitate. Believing that only nickel could produce such an effect, he removed the iron as hydrous ferric oxide and prepared nickel sulfate from the filtrate. These experiments are described in Nicholsons Journal for November, 1800 The native iron of Peru is... 

The native iron-sulfur clusters of many enzymes can be directly observed by EPR spectroscopy (Beinert, 1978). In several cases, appearance of the DNIC signal from nitrogen oxide-treated enzyme (Salerno et al., 1976 Dervartanian et al., 1973 Hyman et al., 1992) or cells (Reddy et al., 1983 Payne et al., 1990) results in the disappearance of these native signals, indicating conversion of the iron from the native cluster coordination to DNIC complexes. However, loss of EPR signal from native clusters does not necessarily correlate with appearance of the DNIC signal (Hyman et al., 1992). 

This is the purest yet described from any locality. In 1786, a mass of native iron, weighing upwards of thirteen tens, was found in South America, a sample of which was sent to the British Museum. It is described as boing soft and compact, although the internal part of tho mess is full of cavities it hod 07ery appearance of having been in a fused state, and was considered the product of a volcanic irruption. No analysis of this sample has been made. 

Small quantities of native iron have been obtained in the immediate vicinity of a coal seam which hod been sponteneously ignited, and was doubtless the result of reduction by the cool samples of this sort pro excessively hard and fine-grained, and give a fracture reaemhiing cast-steel, from which ciroumstonce it has been named native eteel or steely iron. A mass of Otis mineral, weighing sixteen pounds six ounces, was discovered some yean since near Nexy, in the department of the Allier. 

Large masses of native iron have been found in dif- acid the iron is thrown down by excess of ammonia ... 

Metals have been used since prehistoric times. Many primitive iron tools have been excavated. These were probably made from small amounts of native iron found in rock from meteorites. It was not until about 2500 bc that iron became more widely used. This date marks the dawn of the iron age, when people learned how to get iron from its ores in larger quantities by reduction using charcoal. An ore is a naturally occurring mineral from which a metal can be extracted. 

Native iron is most common in iron meteorites. Native mercury is a liquid and extremely volatile. The low boiling point of this fluid can be reached in hot sunlight, so specimens containing free mercury are rare. 

There are only a few minerals that are attracted to a magnet, and only one that sometimes is itself a natural magnet. Those species that are attracted by a magnet include magnetite, pyrrhotite, and native iron. Magnetite occasionally occurs as naturally magnetic specimens, which have the common name lodestone. ... 

As has already been mentioned, iron seldom occurs in the free state in nature on account of the readiness with which it oxidises on exposure to a moist atmosphere. Native iron is frequently of meteoric origin,2 and contains varying quantities of alloyed nickel.3 Usually the nickel ranges from 1 to 10 per cent., but the metallic particles contained in the meteorite which fell near Middlesbrough in 1881 possessed no less than 21-32 per cent, of nickel,4 whilst the Santa Catharina siderite5 contained 34 per cent., and Oktibbeha County siderite 60 per cent, of... 

E. coli R2 Y122F Catalytically inert, native iron site, no radical c... 

D84A/H/E Ala84 catalytically inert, changed iron site, transient Tyr His84 changed iron site, no Tyr Glu84 transient peroxo, native iron site, forms Tyr d, e... 

D237A/N/E Ala237 unstable protein Asn237 catalytically inert, native iron site, transient Tyr Glu237 67n7% activity, native iron site, Tyr H-bonded RTF f... 

Y370F/W Native iron site, Tyr, R1 complex, catalytically inert (Phe370), 1.7% activity (Trp370) k... 

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