Faustite is a rare zinc borate hydroxide mineral with the chemical formula Zn6(BO3)(OH)11(OH)2. It is a secondary mineral typically found in altered zinc deposits.
Faustite usually occurs as fine-grained, radiating aggregates or as coatings. Its color ranges from white to colorless, but can also be tinged with yellow or brown. It is typically transparent to translucent and has a vitreous luster.
The mineral was first described in 1980 and named in honor of George T. Faust (1902-1985), a mineralogist with the United States Geological Survey.
Faustite is often associated with other zinc-bearing minerals such as hydrozincite, smithsonite, and willemite. It forms as a result of the alteration of primary zinc minerals in the presence of boron-rich fluids. Due to its rarity and fine-grained nature, faustite is primarily of interest to mineral collectors and researchers. Its presence can also serve as an indicator of specific geochemical conditions during the formation of ore deposits.
