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Chromite can also be presented in a thin section. The grains seen in thin sections are disseminated with crystals that are euhedral to subhedral. [12] Chromite contains Mg, ferrous iron [Fe(II)], Al and trace amounts of Ti. [5] Chromite can change into different minerals based on the amounts of each element in the mineral.
In chemistry the term chromite has been used in two contexts. Under IUPAC naming conventions, chromate(III) is preferred to chromite. [citation needed] For compounds containing an oxyanion of chromium in oxidation state of +3; For other compounds of chromium(III) as a means of distinguishing a chemical species such as hexacyanochromite(III).
The Pourbaix diagram for chromium in pure water, perchloric acid, or sodium hydroxide [1] [2] 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 ...
The following tests are some examples of those that are used on hand specimens, or on field samples, or on thin sections with the aid of a polarizing microscope. Color; Color of the mineral. Color alone is not diagnostic. For example quartz can be almost any color, depending on minor impurities and microstructure. Streak
Chromite, a FeCr 2 O 4 containing mineral It is used as a commercial source of chromium and its compounds. [ 1 ] It is also used as a catalyst in the synthesis of hydrogen (H 2 ) from the reaction between carbon monoxide and water vapor.
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:
The Pourbaix diagram for chromium in pure water, perchloric acid, or sodium hydroxide [27] [28] 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.
The chemistry of a cumulate can inform upon the temperature, pressure and chemistry of the melt from which it was formed, but the number of minerals which co-precipitate need to be known, as does the chemistry or mineral species of the precipitated minerals. [2] This is best illustrated by an example;