Group 12 element have zinc in its active site. In 1817, cadmium was discovered in Germany as an impurity in zinc carbonate minerals (calamine) by Friedrich Stromeyer and Karl Samuel Leberecht Hermann. It was named after the Latin "cadmia" for "calamine", a cadmium-bearing mixture of minerals, which was in turn named after the Greek mythological character, Κάδμος Cadmus, the founder of Thebes. Stromeyer eventually isolated cadmium metal by roasting and reduction of the sulfide. In 1927, the International Conference on Weights and Measures redefined the meter in terms of a red cadmium spectral line (1 m = 1,553,164.13 wavelengths). This definition has since
Ore Mountains role on the Saxon side of the border. For example, in Hermsdorf/Erzgeb. in the Eastern Ore Mountains, calcite is mined, and near Lengefeld in the Central Ore Mountains, dolomite marble is extracted. For the first time in two decades, an ore mine was opened in Niederschlag near Oberwiesenthal on 28 October 2010. It is expected that 50,000-130,000 tons of fluorspar per year will be extracted there. In the Czech part of the Ore Mountains, tourism has gained a certain importance, even though the Krkonoše are more important for domestic tourism. In addition, mining still plays a greater role, particularly coal