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Chromium is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel.
Chromium concentrations in soil diversify depending on the different compositions of the sediments and rocks that the soil is made from. The chromium present in soil is a mixture of both Cr(VI) and Cr(III). [25] Certain types of chromium such as Chromium-VI has the capability to pass into the cells of organisms. Dust particles from industry ...
Corundum is a crystalline form of aluminium oxide (Al 2 O 3) typically containing traces of iron, titanium, vanadium, and chromium. [3] [4] It is a rock-forming mineral.It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. [7]
[5] [6] Various amalgams of silver and mercury or other metals and mercury do occur rarely as minerals in nature. An example is the mineral eugenite (Ag 11 Hg 2 ) and related forms. [ 7 ] Silver nuggets, wires, and grains are relatively common, but there are also a large number of silver compound minerals owing to silver being more reactive ...
Chromium(III) oxide (or chromia) is an inorganic compound with the formula Cr 2 O 3. It is one of the principal oxides of chromium and is used as a pigment. In nature
The primary chromium ore is the mixed metal oxide chromite, FeCr 2 O 4, found as brittle metallic black crystals or granules. Chromite ore is heated with a mixture of calcium carbonate and sodium carbonate in the presence of air. The chromium is oxidized to the hexavalent form, while the iron forms iron(III) oxide, Fe 2 O 3:
Chromium compounds are compounds containing the element chromium (Cr). Chromium is a member of group 6 of the transition metals. The +3 and +6 states occur most commonly within chromium compounds, followed by +2; charges of +1, +4 and +5 for chromium are rare, but do nevertheless occasionally exist. [3] [4]
Hexavalent chromium (chromium(VI), Cr(VI), chromium 6) is any chemical compound that contains the element chromium in the +6 oxidation state (thus hexavalent). [1] It has been identified as carcinogenic, which is of concern since approximately 136,000 tonnes (150,000 tons) of hexavalent chromium were produced in 1985. [ 2 ]