Copper mining in the United States the northwest part of the state in the early 1850s, and mining began in 1855. The ore is massive sulfide and disseminated ore in mica schist and gneiss, and amphibole schist and gneiss. The principal ore mineral is chalcopyrite, which occurs with pyrrhotite and pyrite, The mine operated until 1883, then worked sporadically until large-scale mining began in 1957. The mine closed for good in 1962. Total production was 31,000 tonnes of copper, 9,400 ounces of gold, and 145,000 ounces of silver. Copper was mined at Creta from 1965 to about 1975. The ore 2% to 4.5% copper as chalcocite
Ore Mountains out Germany-wide in the 1950s the Ore Mountains formed major unit group 42: Even after the reclassification of natural regions by the Federal Agency for Nature Conservation in 1994 the Ore Mountains, region "D16", remained a major unit group with almost unchanged boundaries. However, at the beginning of the 21st century, the working group "Naturhaushalt und Gebietscharakter" of the Saxon Academy of Sciences ("Sächsische Akademie der Wissenschaften") in Leipzig merged the Ore Mountains with the major unit group of Vogtland to the west and the major landscape units of Saxon Switzerland, Lusatian Highlands and Zittau Mountains to the east into