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The color of amethyst has been demonstrated to result from substitution by irradiation of trivalent iron (Fe 3+) for silicon in the structure, [4] [12] in the presence of trace elements of large ionic radius, [3] and to a certain extent, the amethyst color can naturally result from displacement of transition elements even if the iron ...
Iron meteorites, also called siderites or ferrous meteorites, are a type of meteorite that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Most iron meteorites originate from cores of planetesimals, [3] with the exception of the IIE iron meteorite group. [4]
Stony-iron meteorites or siderolites are meteorites that consist of nearly equal parts of meteoric iron and silicates. This distinguishes them from the stony meteorites, that are mostly silicates, and the iron meteorites, that are mostly meteoric iron. [1] Stony-iron meteorites are all differentiated, meaning that they show signs of alteration.
Elemental iron is virtually absent on the Earth's surface except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths.Although iron is the fourth most abundant element in Earth's crust, composing about 5% by weight, [4] the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive ...
Type 1 telluric iron contains a significant amount of carbon. Type 1 is a white nickel cast-iron, containing 1.7 to 4% carbon and 0.05 to 4% nickel, which is very hard and brittle and does not respond well to cold working. The structure of type 1 consists mainly of pearlite and cementite or cohenite, with inclusions of troilite and silicate.
Mineralogy applies principles of chemistry, geology, physics and materials science to the study of minerals. Mineralogy [n 1] is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts.
Meteoric iron also has an effect on the Earth's atmosphere. When meteorites descend through the atmosphere, outer parts are ablated. Meteoric ablation is the source of many elements in the upper atmosphere. When meteoric iron is ablated, it forms a free iron atom that can react with ozone (O 3) to form FeO. This FeO may be the source of the ...
Ironstone (sandstone with iron oxides) from the Mississippian Breathitt Formation, Mile Marker 166, I-64, Kentucky. Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron ore compound from which iron (Fe) can be smelted commercially.