What Is Chromite Used For

Chromite – Mtoroshanga, Makonde District, Mashonaland West, Republic of zimbabwe

Chromite is an oxide mineral that an atomic number 26 chromium oxide with formula: FeCr2O4. Information technology is belonging to the spinel group. Chromite is the most important ore of chromium. Crystals are uncommon, just when found they are octahedral. Chromite is normally massive or in the form of lenses and tabular bodies, or it may be disseminated as granules. It is sometimes found as a crystalline inclusion in diamond. Chromite is dark brown to black in color and tin contain some magnesium and aluminum. Chromite is nigh normally found as an accessory mineral in iron- and magnesium-rich igneous rocks or concentrated in sediments derived from them. It occurs as layers in a few igneous rocks that are peculiarly rich in iron and magnesium. About pure chromite is plant in like layers in sedimentary rocks. The layers are preserved when the sedimentary rocks metamorphose to grade serpentinite. Referred to equally chromitites, these rocks are the most important ores of chromium. The weathering of chromite ore bodies tin also lead to its concentration in placer deposits.

Proper noun: For its CHROMium content.

Association: Olivine, enstatite, plagioclase, serpentine, magnetite, ilmenite, pyrrhotite, pentlandite, ulvospinel.

Polymorphism & Series: Forms serial with magnesiochromite and hercynite.

Chromite Composition: FeCr20 4. FeO = 32.0 per cent, Cr20 3 = 68.0 per cent. The fe may exist replaced past magnesium, and the chromium by aluminum and ferric atomic number 26.

Diagnostic Features: The submetallic luster commonly distinguishes chromite, only the greenish borax bead is diagnostic

Mineral Grouping: Spinel group.

Crystallography: Isometric; hexoctahedral. Habit octahedral. Crystals small and rare. Commonly massive, granular to compact.

Environment: In metamorphic Serpentine deposits, and besides in ultrabasic igneous rocks, and in placer deposits. May also occur in meteorites.

Chemic Properties

Chemical Classification	Oxide minerals, Spinel group
Formula	(Atomic number 26, Mg)Cr2O4
Mutual Impurities	Mg,Mn,Zn,Al,Ti

Chromite Physical Backdrop

Crystal habit	Octahedral rare; massive to granular
Color	Black to brown black; brown to brownish black on sparse edges in transmitted light
Streak	Brown
Luster	Resinous, Greasy, Metallic, Sub-Metallic, Tiresome
Cleavage	None Observed
Diaphaneity	Translucent, Opaque
Mohs Hardness	5,five
Crystal System	Isometric
Tenacity	Brittle
Density	4.v – 4.viii g/cm3 (Measured) 5.12 g/cm3 (Calculated)
Fracture	Irregular/Uneven, Hackly, Sub-Conchoidal
Parting	Parting may develop along {111}
Other characteristics	Weakly magnetic

Chromite Optical Properties

Type	Isotropic
Colour / Pleochroism	Not-pleochroic
RI values:	northward = 2.08 – ii.16
Twinning	On {111}
Birefringence	0.0
Relief	Very High

Occurrence of Chromite

A cumulus mineral in ultramafic portions of layered mafic igneous rocks; an accessory mineral in tall-type peridotites; also detrital. Common in all meteorites, except carbonaceous chondrites, and in lunar mare basalts.

Chromite is a mutual constituent of peridotite rocks and the serpentines derived from them. One of the showtime minerals to dissever from a cooling magma; big chromite ore deposits are idea to have been derived past such magmatic differentiation.

The important countries for its production are New Caledonia, Southern Rhodesia, Greece, U.s.a.Due south.R., and Canada. Found only sparingly in the United States. Pennsylvania, Maryland, North Carolina, and Wyoming have produced it in the past. California is the only important producing state at present (1940). Also found in the Philippine Islands.

Chromite Uses Area

The simply ore of chromium. Chromium is used with various other metals to give hardness to steel, also every bit a plating material because of its non-corrosive nature. Chromite bricks are used to a considerable extent as linings for metallurgical furnaces, because of their neutral and refractory character. The bricks are commonly fabricated of crude chromite and coal tar but sometimes of chromite with kaolin, bauxite, or other materials. Chromium is a constituent of certain green, yellow, orangish, and red pigments and of similarly colored dyes.

Distribution

Widespread. From Gassin, Var, France.
Large crystals from Hangha, Sierra Leone.
At Tiebaghi, New Caledonia.
Equally economic deposits in: the Bushveld complex, Transvaal, Southward Africa.
From the Neat Dyke, Zimbabwe.
From many localities in Turkey.
At Saranay and elsewhere in the Ural Mountains, Russia.
From the Moa commune, northern Cuba.
On Luzon, Philippines.
From the Stillwater complex, Montana, U.s..

References

• Bonewitz, R. (2012). Rocks and minerals. second ed. London: DK Publishing.
• Dana, J. D. (1864). Manual of Mineralogy… Wiley.
• Handbookofmineralogy.org. (2019). Handbook of Mineralogy. [online] Available at: http://www.handbookofmineralogy.org [Accessed 4 Mar. 2019].
• Mindat.org. (2019): Mineral information, data and localities.. [online] Available at: https://world wide web.mindat.org/ [Accessed. 2019].