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
Broken Hill ore deposit of the main lode. The ore often consists up to 100% lead-zinc sulfides, with little or no pyrite, chalcopyrite or gangue sulfides. The footwall to the mineralization is a psammopelite gneiss, consisting of feldspar, quartz, garnet, biotite and amphibole, with a pelite gneiss on the hanging wall. The footwall gneiss contains anomalous mineral chemistries including a rare lead-rich feldspar and manganese-rich garnet chemistries. Ore is predominantly hosted at this stratigraphic break, but much of the ore body is structurally remobilised or offset into both the hangingwall and footwall, and the geometry of the ore deposit is particularly complex on the