Ferberite Crystal Yaogangxian Mine Hunan Province China

You are bidding on a beautiful specimen of Ferberite crystals from the Yaogangxian Mine, Chenzhou, Hunan Province, China.

Ferberite belongs to a series with another mineral, Huebnerite , MnWO4. Huebnerite is the Manganese rich end member while ferberite is the iron rich end member.  They are major ores of tungsten which is used as a filament in light bulbs and is used in carbide drilling equipment.  Wolframite is the name of the series and the name applied to indistinguishable specimens and specimens intermediate between the two end members. Most specimens found in nature fall within 20 - 80% range of the series and these are termed wolframites, (Fe, Mn)WO4. Only if they are 80% or more iron are they called ferberite. Ferberite's iron content causes the dramatic differences between it and hubnerite (wolframite is of course intermediate). Ferberite tends to be black colored, with a black streak, is opaque with a nearly submetallic luster, is denser, has crystals with a different elongation and can be weakly magnetic. Huebnerite, however, tends to be light in color, with a lighter streak, more transparent and less dense. Ferberite is the rarer member of the series.  

It measures 1 1/4 x  1 3/8  x 3/4 inches and weighs 1 ounce.  This will make a great addition to your collection. 

Shipping to US addresses will be $1.95. (Postage 1.56, padded mailer .20, delivery confirmation .19)

Thanks for looking.