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Chromite is a crystalline mineral composed primarily of iron(II) oxide and chromium(III) oxide compounds. It can be represented by the chemical formula of Fe Cr 2 O 4 . It is an oxide mineral belonging to the spinel group .
The mineral chromite is an iron chromium oxide with empirical formula FeCr 2 O 4. Structurally, it belongs to the spinel group. Magnesium can substitute for iron in variable amounts as it forms a solid solution with magnesiochromite (MgCr 2 O 4);. [1] Zincochromite is another example.
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
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:
Chromitite and anorthosite layered igneous rocks in Critical Zone UG1 of the Bushveld Igneous Complex at the Mononono River outcrop, near Steelpoort, South Africa. A layered intrusion is a large sill-like body of igneous rock which exhibits vertical layering or differences in composition and texture.
Crocoite is commonly found as large, well-developed prismatic adamantine crystals, although in many cases are poorly terminated. Crystals are of a bright hyacinth-red color, translucent, and have an adamantine to vitreous lustre.
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Discordant rock, one that cuts across the existing bedding: as in one of the main types of igneous intrusion, or as in the sedimentary clastic dikes; Discordant strata, rock layers with mismatches in the geologic record; Discordant coastline, when the bands of rock run perpendicular to the coast