In 1921 Adolf Gottfried began with the mining of high-grade clays at Fonsau in the Egerland region in the Wildsteiner Basin. By the beginning of the First World War the Adolf Gottfried Tonwerke (clay-works) had grown into a enterprise employing more than 300 people with eight open clay pits. From here the different grades of clay, in raw, dry and ground form, were delivered to refractories and ceramics factories all over Europe.