The Mineral Wolframite

Wolframite is an iron, manganese, and tungsten, mineral. It is intermediate between Ferberite and Huebernite. Ferberite is an iron rich member while Huebnerite is a manganese rich end member. It is associated with tin ore and granite. It has sub metallic to metallic luster.
Wolframite is the isomorphous mixture of iron tungstate and manganese. The mineral Hubnerite and Ferbirite are pure end members of the Wolframite mineral. It occurs in lamellar and granular masses. Wolframite is found with Cassiterit. It is comparatively rare mineral and is associated With Quatz, Bismuth, Schellite, Galena, Pyrite and the like.

The term Wolframite is used, when specimen found in nature fall in the 20-80% range of the series. If they are pure with more than 80% manganese, they are known as Huebnerite, and if they have more than 80% iron, they are known as Ferbirite.

Occurrence
Wolframite mineral is found in pegmatite dikes and granite. It is associated with Cassiterite. It also occurs in placer deposits and sulfide veins. The Wolframite mineral was found in Europe in Bohemia. China is the world’s largest supplier of tungsten ore with about 60%. Other producers of Wolframite are Australia, Russia, Portugal, South Korea, Thailand and United States. Its origin is pneumatolytic.

Tungsten and its alloys are used as filaments for television tubes, electric tubes and electrons. It may also be used in electrical contact points for automobile distributors, heating element for electrical furnaces and high temperature applications and in the space missile. In petroleum industries and metal working mining, Tungsten carbide is an important compound. Magnesium tungstate and calcium are other important tungsten compounds, and are used in tungsten disulfide and fluorescent lighting. Tungsten compounds are also used in paint, chemical and tanning industries.

Derivation Of Name
The Wolframite word is derived from “wolf Ramm" from german. The name was given by Johan Gottschalk Wallerious and it is named for tungsten content, “wolfram" means tungsten in German.

Chemical Formulae
(Fe, Mn) WO4

Physical characteristics
Color is black to brown or gray.
Luster is sub metallic to resinous.
Crystal system is monoclinic.
Transparency crystals are translucent to opaque.

Hardness is 4-4.5

Fracture is uneven.

The streak is red, brown to black.

Specific gravity is 7.0-7.5.

Crystal habits: including flat they are heavily modified and in tabular form.
These crystals are elongated with c axis and flatten in the axial direction.

Uses
The Wolframite mineral is an important tungsten ore mineral. Tungsten is used as a hardening metal in the production of tool steel and steel alloys. It is most valuable for steel hardening metals. Tungsten steel is very tough steel. In the manufacture of contact points, tungsten is used as the substitute for platinum. In fire proofing of cloth, sodium tungstate is used as impregnate wood and render it fireproof. Wolframite mines were strategic asset in world war II, due to its tools and munitions

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