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Wolframite



Wolframite

General
CategoryMineral
Chemical formula(Fe,Mn)WO4
Identification
ColorBlack (ferberite) to brown (huebnerite)
Crystal habitTabular crystals, sometimse prismatic
Crystal systemMonoclinic 2/m
CleavagePerfect 010
FractureUneven to rough
Mohs Scale hardness4-4.5
LusterSubmetallic to resinous
Refractive indexOpaque
PleochroismNone
StreakBlack to brown
Specific gravity7 - 7.5
Fusibility3 - 4 to magnetic globule
SolubilityInsoluble

Wolframite (Fe,Mn)WO4, is an iron manganese tungstate mineral that is the intermediate between ferberite (Fe2+ rich) and huebernite (Mn2+ rich). Along with scheelite, the wolframite series are the most important tungsten ore minerals. Wolframite is found in quartz veins and pegmatites associated with granitic intrusives. Associated minerals include cassiterite, scheelite, bismuth, quartz, pyrite, galena, sphalerite, and arsenopyrite.

Additional recommended knowledge

It was historically found in Bohemia, Saxony, and Cornwall. China reportedly has the world's largest supply of tungsten ore with about 60%. Other producers are Portugal, Russia, Australia, Thailand, Korea, Bolivia, and the United States.

The name comes from German Wolfram for tungsten[citation needed] and provides the chemical symbol, W, for tungsten.

Wolframite was highly valued as the main source of the metal tungsten, a strong and dense material with many military uses. In WWII wolframite mines were a strategic asset as the metal was used in munitions. German industrial tools mostly used tungsten carbide. Also, tungsten was used in specialized armor piercing ammunition. This importance has decreased with the increasing use of depleted uranium for many of these applications.

See also

References

  • Webmineral data
  • Mindat.org
  • spiritone.com
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Wolframite". A list of authors is available in Wikipedia.
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