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
Mining in North Korea handle 10 million tons of zinc ore. Conventional flotation methods are adopted to extract lead and zinc concentrates. Other products from the mine are sphalerite, chalcopyrite, and galena. In gold alone the nation is estimated to hold around 2,000 metric tonnes of reserves, which at a gold value of $1,200/ounce, would give a total worth of $84.6 billion. Other available resources include iron, with 5 billion tonnes of 50% iron-content ore in reserve, nickel, with 36,000 tonnes of the pure metal, and zinc metal, with around 21,100,000 tonnes. The Daebong Mine, located on the border of Gapsan and Woonheung in