Group 12 element zinc and cadmium which makes geological separation unlikely. As a consequence, cadmium is produced mainly as a byproduct from mining, smelting, and refining sulfidic ores of zinc, and, to a lesser degree, lead and copper. One place where metallic cadmium can be found is the Vilyuy River basin in Siberia. Although mercury is an extremely rare element in the Earth's crust, because it does not blend geochemically with those elements that constitute the majority of the crustal mass, mercury ores can be highly concentrated considering the element's abundance in ordinary rock. The richest mercury ores contain up to 2.5% mercury
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