Hübnerite is a mineral consisting of manganese tungsten oxide, with a chemical formula MnWO4. It typically occurs in association with high-temperature hydrothermal vein deposits and altered granites and in alluvial deposits. Hübnerite is the manganese endmember of the wolframite solid solution series, with ferberite (FeWO4) the opposite iron endmember. Color differences between members of the wolframite family are clear and marked, with the color of hübnerite varying from yellowish brown to reddish brown. It was first described in 1865 for an occurrence in the US state of Nevada and was named after the German mining engineer and metallurgist Adolf Hübner. This stacked image, composed of 38 individual photographs, shows red hübnerite crystals with quartz extracted from the Pasto Bueno mine in Pallasca Province, Peru.Photograph credit: Ivar Leidus