| Iron Chromium
Oxide
FeCr2O4
 The
principle ore of chromium, as a refractory component, as a dye and
as mineral specimens.
Chromite is the most important ore of chromium from which it derives
its name. Chromium is an important metal and has a wide range of
industrial uses.
Chromite forms in deep ultra-mafic magmas and is one of the first
minerals to crystallize. It is because of this fact that chromite
is found in some concentrated ore bodies. While the magma is slowly
cooling inside the Earth's crust, chromite crsytals are forming
and because of their density, fall to the bottom and are concentrated
there.
 Although
its primary origin is ultra-mafic rocks such as peridotites, chromite
is also found in metamorphic rocks such as serpentites. Chromite,
as is indicated by its early crystallization is resistant to the
altering affects of high temperatures and pressures. Thus it is
capable of going through the metamorphic processes unscathed, while
other minerals around it are being altered to serpentine, biotite
and garnets. This characteristic also explains chromites use as
a refractory component in the bricks and linings of blast furnaces.
Usually magnesium is present in chromite substituting for the iron
and in fact a solid solution series exists between chromite and
the much rarer mineral magnesiochromite. All chromite specimens
in nature contain some magnesium, likewise all natural magnesiochromites
contain some iron. Magnesiochromite is grayer in color and in streak
and has a slightly lower density than chromite at a specific gravity
of 4.2 to 4.4.
| Hardness |
Associated Minerals |
Chemical/Typical composition |
Colour |
Characteristics |
Luster |
Field Indicators |
| 5.5 |
olivine talc Serpentine
uvarovite pyroxenes biotite magnetite anorthie |
Oxides and Hydroxides |
brownish black to
a deep dark black |
Weakly magnetic
and an octahedral parting is sometimes seen |
metallic to greasy |
Crystals babit, associations
with ultra-basic minerals and parting |
Uses
The following uses for chromium are gathered from a number of sources
as well as from anecdotal comments. I'd be delighted to receive
corrections as well as additional referenced uses (please use the
feedback mechanism to add uses).
• used to harden steel, to manufacture stainless steel, and
to form alloys
• used in plating to produce a hard, beautiful surface and
to prevent corrosion.
• used to give glass an emerald green colour. It is responsible
for the green colour of emeralds and the red colour of rubies
• wide use as a catalyst
• dichromates such as K2Cr2O7 are oxidising agents and are
used in quantitative analysis and also in tanning leather
• lead chromate as chrome yellow is a pigment
• compounds are used in the textile industry as mordants
• used by the aircraft and other industries for anodising
aluminium
• the refractory industry uses chromite for forming bricks
and shapes, as it has a high melting point, moderate thermal expansion,
and stable crystalline structure
• tanning leather
 Large
deposits of chromite are found in the northern areas of Pakistan.Hilly
tracts of Gilgit,chitral,bisham and adjoining parts are main source
of obtaining chromite which have the purity percentage according
to the buyers in the international market.We also have large deposits
in the Muslimbagh area of Baluchistan province which is also considered
main source of supply to the international buyers.
BESIDES
IT WE HAVE THE GRADES OF CHROMITE ORE:
Cr2O3 = 32% - 39%
Cr2O3 = 40% - 42%
Cr2O3 = 42% - 44%
Cr2O3 = 46% - 48%
Cr2O3 = 48% - 50%
Cr2O3 = 50% & ABOVE
WE CAN PROVIDE AND SUPPLY ANY SIZE OF THIS MINERALS AS PER THE SPECIFICATIONS
OF BUYERS
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