Hübnerite

Hübnerite is a manganese tungstate mineral with the chemical formula MnWO4. It is part of the wolframite group and represents the manganese-rich end-member of the (Fe,Mn)WO4 solid solution, with ferberite (FeWO4) and other wolframite varieties at the iron-rich end. Hübnerite crystallizes in the monoclinic system and commonly forms elongated prismatic crystals, often in hydrothermal tungsten-bearing veins.

In terms of physical properties, hübnerite ranges in color from brown to brownish-black, with a pale brown streak. It has a metallic to submetallic luster and is typically opaque, though thin edges may be translucent. The mineral’s hardness is about 4.5 on the Mohs scale, and its specific gravity is approximately 7.0–7.3, reflecting its dense oxide composition. Crystals are commonly prismatic and may occur as coarse aggregates in suitable ore bodies.

Hübnerite occurs primarily in tungsten-rich hydrothermal deposits and is frequently found alongside other tungsten minerals such as scheelite, wolframite, and ferberite, as well as quartz and cassiterite in vein systems. It has a terrestrial distribution worldwide, with notable occurrences in various regions that host tungsten ore deposits. The mineral is of interest as a tungsten ore, contributing to the total tungsten resource alongside other members of the wolframite group. It is also collected as a specimen mineral by mineral enthusiasts.