21. Metasomatic altered aureoles can localize the deposition of metallic ore minerals and thus are of economic interest. 22. For copper, acids are generally needed to enhance solubility of the ore minerals within the solution. 23. Mineral Fork was so named on account of deposits of the lead ore minerals near its course. 24. Descloizite and mottramite were the main ore minerals in each of these deposits, which are now exhausted. 25. The principal ore mineral was chalcocite, although native copper predominated in the lower part of the beds. 26. It occurs in sedimentary marine evaporites and is a major potassium ore mineral in the Carlsbad Deposits of New Mexico. 27. In the supergene sulfide enriched zone, ore minerals include pearceite, proustite, tetrahedrite, polybasite, and pyrargyrite. 28. At about 13.8 fracturing soon followed, altering the dacite and depositing ore minerals and gangue in the veins. 29. In most forest ecosystems, sulfate is derived mostly from the atmosphere; weathering of ore minerals and evaporites contribute some sulfur. 30. A key objective in the metallurgical treatment of any ore is the separation of ore minerals from gangue minerals within the rock.
