Braunerite was discovered in the Svornost Mine in western Bohemia of the Czech Republic. It has a new, unequal, three-dimentional structure type comprised of networks of uranyl and carbonate ions, with a high structural complexity second only to another new carbon mineral, ewingite. The Department of Mineralogy and Petrology of the National Museum, Prague, Czech Republic and the Natural History Museum of Los Angeles County, USA, both contain samples of this new carbon mineral in their collections.