Covellite from Iowa County, Wisconsin, USA
USA | |
| AmMin 44:995-1009 |
| Heyl, A., A. F. Agnew, E. J. Lyons & C.H. Behre Jr. (1959), The geology of Upper Mississippi Valley Zinc-Lead District: U.S. Geological Survey Professional Paper 309: 269-270. |
USA | |
| AmMin 44:995-1009 |
| Heyl, A., A. F. Agnew, E. J. Lyons & C.H. Behre Jr. (1959), The geology of Upper Mississippi Valley Zinc-Lead District: U.S. Geological Survey Professional Paper 309: 269-270. |