New Almaden hydrothermal deposition of cinnabar from deep within the earth is found in a gangue of silica-carbonate rock formed locally by hydrothermal alteration of serpentine. The Guadalupe mine produced about 10% as much mercury as the New Almaden. There are several smaller mines in the mining district, but their ore production was not significant. The only significant quicksilver ore is cinnabar; other sulfides are present in small quantities. Mining, other than a single placer deposit of cinnabar, was underground. There is a high probability of undiscovered high-grade ore which could be found and exploited using modern techniques. Mining operations resulted in
Glassworks Museum of the Ore Mountains in 1750, of Purschenstein Castle was placed under protection. Through grants the house, which is owned by the parish, was refurbished and, with the help of the local branch of the Ore Mountain Club, turned into a museum. In May 1996 the Ore Mountain Glassworks Museum ("Erzgebirgische Glashüttenmuseum") opened its first exhibition. It contained pieces from the roughly 800-year-old glassmaking industry in the Ore Mountains. The exhibition focusses particularly on the history of the Heidelbach Glassworks from 1488 to 1827. Since opening, the museum has also been enhanced by the replica of a glass melting furnace in an adjoining building,