Manganite is a mineral of a combined manganese oxide and manganese hydroxide and fits in the monoclinic crystal system. It is most commonly found as amorphous crusts and precipitates in weathered rocks and surface soils. It more rarely occurs as shorter or longer striated prismatic crystals, steel grey or black metallic, with their ends perpendicularly terminated. This specimen is from Ilfeld in the Harz Mountains, Germany, and measures 140 mm across.