Formula: (Fe,Mn)WO4 - Monoclinic
The ferberite- huebnerite series is a series of tungstate mineralss with varying proportions of iron to manganese. They are relatively high temperature minerals characteristically found in quartz veins associated with granite.
MARATHON COUNTY: Both ferberite and huebnerite have been reported associated with topaz, cassiterite and other rare minerals from the McGuire Pit, west of Wausau. The ferberite-hubnerite form “dark red-brown to black crystals to 1.5 mm on and in albite and quartz”.(Buchholz et al., 2004).