Constellation Copper's Lisbon Valley copper mine in San Juan County, southeastern Utah began mining in 2005, and produced its first copper in 2006. The copper deposit is in sandstones of the Dakota Sandstone and Burro Canyon Formation. The primary copper mineral is chalcocite, which is thought to have been deposited from solutions ascending through the Lisbon Valley Fault. Above the water table, chalcocite has been oxidized to malachite, azurite, tenorite, and cuprite. On November 30, 2007, Constellation announced that it would stop mining in 2008, because of unexpectedly low copper recovery. The company will continue to recover copper by heap-leaching already-mined ore as long as profitable.