Location

Yaogangxian Mine, Hunan Province, China

Description

Jet black, vitreous 30 x 15 x 5 mm crystals of Ferberite with small clear quartz crystals the largest of which measures 18mm. No damage.

Ferberite is the iron endmember of the manganese - iron wolframite solid solution series. The manganese endmember is hübnerite. Ferberite is a black monoclinic mineral composed of iron(II) tungstate, FeWO4.

Ferberite occurs as granular masses and as slender prismatic crystals. It ahs a Mohs hardness of 4.5 and a specific gravity of 7.4 to 7.5. Ferberite typically occurs in pegmatites, granitic greisens and high temperature hydrothermal deposits. It is a minor ore of tungsten. It was discovered in 1863 in Sierra Almagrera, Spain. It was named after Moritz Rudolph Ferber (1805-1875).

Price $125