hureaulite

Hureaulite is a rare phosphate mineral with the chemical formula Mn5(PO4)2(OH)2. It is a member of the triploidite group and is characterized by its manganese content. The mineral typically occurs in granular or massive forms, and can also be found as small prismatic crystals. Its color ranges from pale pink to reddish-brown, and it possesses a vitreous to resinous luster. Hureaulite is often found in association with other manganese-bearing minerals in pegmatites and hydrothermal deposits. It was first discovered in the Hureaux mine in Limousin, France, which gives it its name. The mineral is relatively soft, with a Mohs hardness of around 4.5 to 5, and it has a specific gravity of approximately 3.2. While not economically significant, hureaulite is of interest to mineral collectors and geologists for its unique chemical composition and occurrence in specific geological environments. It is considered a secondary mineral, forming through the alteration of primary manganese phosphates.