Zinc for discovering pure metallic zinc, even though Swedish chemist Anton von Swab had distilled zinc from calamine four years previously. In his 1746 experiment, Marggraf heated a mixture of calamine and charcoal in a closed vessel without copper to obtain a metal. This procedure became commercially practical by 1752. William Champion's brother, John, patented a process in 1758 for calcining zinc sulfide into an oxide usable in the retort process. Prior to this, only calamine could be used to produce zinc. In 1798, Johann Christian Ruberg improved on the smelting process by building the first horizontal retort smelter. Jean-Jacques Daniel
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