Hübnerite
Image: <a href="//commons.wikimedia.org/wiki/User:Iifar" title="User:Iifar">Ivar Leidus</a> (CC BY-SA 4.0)
Mineral NameHübnerite
Chemical FormulaMnWO₄
Mohs Hardness4.5
Crystal Systemmonoclinic
Streak Coloryellowish-brown to reddish-brown
Cleavageperfect on {010}
Fractureuneven to subconchoidal
Specific Gravity7.12
Colorsdark brownish red, black
Transparencytranslucent to opaque
Type LocalityPasto Bueno, Ancash, Peru
Mineral Grouptungstates
Usesore of tungsten, collector
Associated Mineralsquartz
Rarityuncommon
Description
This specimen features a striking cluster of dark brownish-red to black, elongated, blade-like hübnerite crystals, intergrown with clear to milky white quartz crystals.
Geological Context
Hübnerite typically forms in high-temperature hydrothermal veins associated with granitic intrusions, often found in pegmatites and greisens. It is a primary ore mineral of tungsten.
