Group 12 element by mass, and even the leanest concentrated deposits are at least 0.1% mercury (12,000 times average crustal abundance). It is found either as a native metal (rare) or in cinnabar (HgS), corderoite, livingstonite and other minerals, with cinnabar being the most common ore. While mercury and zinc minerals are found in large enough quantities to be mined, cadmium is too similar to zinc and therefore is always present in small quantities in zinc ores from where it is recovered. Identified world zinc resources total about 1.9 billion tonnes. Large deposits are in Australia, Canada and the United States with the
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,