WOLFRAMITE (FERBERITE), Tasna Mine BOLIVIA (small cabinet)

Ferberite is the iron-rich endmember of the manganese-iron wolframite solid solution series, with hübnerite representing the manganese endmember. This black monoclinic mineral is primarily composed of iron(II) tungstate, or FeWO4. Both ferberite and hübnerite typically contain divalent cations of iron and manganese, with wolframite serving as the intermediate species in the series. Ferberite is found in granular forms and slender prismatic crystals, exhibiting a Mohs hardness of 4.5 and a specific gravity ranging from 7.4 to 7.5. It is commonly located in pegmatites, granitic greisens, and high-temperature hydrothermal deposits, and is considered a minor tungsten ore. Discovered in 1863 in Sierra Almagrera, Spain, ferberite is named in honor of the German mineralogist Moritz Rudolph Ferber.