Chromite is an oxide mineral made up of iron, chromium, and oxygen (FeCr2O4). Chromium can be dark gray or black in color with a metallic to submetallic luster having a high specific gravity. It occurs in ultrabasic and underlying igneous rocks and in the sedimentary and metamorphic rocks manufactured when chromite-led rocks are altered by heat or weathering.
Chromite is the only economic ore of chromium with a necessary element for a variety of chemical, and manufactured products. Several other minerals have chromium. However, none of them are discovered in deposits that can be commercially mined to made chromium by chromite ore manufacturers.
Characteristics of Chromite Ore
You can find chromite as a challenge to identify. Several characteristics must be taken into consideration to differentiate chromite from other metallic ores. The identification of chromite by hand specimen needs an examination of luster, specific gravity, color, and an organic brown streak. The most critical hint to identify chromite is its link with metamorphic rocks and ultrabasic igneous rocks such as serpentinite.
Sometimes chromite is slightly magnetic. This magnetic property can confuse chromite with magnetite. Ilmenite and chromite have similar features. Careful observations of streak, hardness, and specific gravity are needed to distinguish these minerals in hand specimens.
Chromite and Solid Solution
Magnesium substitutes frequently for iron in chromite. A series of robust solution exists between the mineral chromite (FeCr2O4) and the isomorphous mineral magnesiochromite (MgCr2O4). Intermediate specimens might be rich in iron ((Fe, Mg)Cr2O4) or magnesium ((Mg, Fe)Cr2O4). For communication convenience, these minerals are referred collectively as “chromite.”
Some mineralogists provide a generalized chemical composition of (Mg, Fe)(Cr,Al)2O4 for chromite. The composition identifies multiple solid solution paths between hercynite (FeAl2O4), chromite and spinel (MgAl2O4), magnetite (Fe3O4), magnesiochromite (MgCr2O4), and magnesioferrite (MgFe2O4).
Due to many different compositions in the solid solution series, metallurgists and geologists often consider “chromite” to be a member of the solid solution series that contains a significant Cr2O3 content.
Uses of Chromium and Chromite
Chromium is a metal that is used to induce toughness, hardness, and chemical resistance in steel. The alloy manufactured is known as “stainless steel.” When chromium is alloyed with nickel and iron, it produces a popular alloy known as “nichrome,” which resists high temperatures and used to make ovens, heating units, and other appliances. Chromium with Thin coatings alloys is used as a plating on appliances, auto parts, and other products. These are alluded to as “chrome plated.” Chromium is also used to make super-alloys, which can perform well in the corrosive, hot, and high-stress environment of jet engines.
Chromium is a name that comes from the Greek word “Chroma,” which means “color.” Chromium is typically used as a pigment in paint. The yellow lines painted down the focus of highways, and the yellow paint used on school buses are often “chrome yellow” – a color produced from chromium pigment.
Chromium is a vital pigment in several types of ink, dye, paint, and cosmetics—trace amounts of chromium manufacture the color in several gemstones and minerals. Tiny amounts of chromium happen the pink color of sapphires, the red color of ruby, and the green color of emerald.
Production and Recycling of Chromium in the USA
In the United States, chromium is not mined. The chromium used by the USA industry arrives from: A) other countries in the shape of ferrochromium, chromite ore, or chromium metal. B) Chromium is recovered from recycled metals. Today, more than half of the chromium consumed in the US is from recycling.
Since chromium is necessary for the United States’ resistance and prosperity, the government keeps up a reserve of chromite mineral, ferrochromium, and chromium metal for use in a national crisis. This kind of disaster could happen if the United States was engaged with war, and the enemy forestalled the conveyance of chromite and chromium items via ocean transport. Moreover, little chromite deposits have been situated in the United States, which could be mined in the event that they are required.
Diamond and Chromite Exploration
Kimberlite, a kind of rock, which holds several of the world’s most crucial diamond deposits, typically contains small amounts of ilmenite, chromite, and certain kinds of garnet. Since these minerals discovered in very small amounts, they are more common in the rock than diamonds.
Since these minerals don’t happen together in most different kinds of rocks, they can be an important indicator of a close-by kimberlite body in case they are found in stream dregs, icy tills, lingering soils, center examples, or well cuttings. Probably the best precious stone stores on Earth were found utilizing the geology of indicator minerals.