Chalcocite from Carroll County, Maryland, USA
USA | |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Mines of the Washington D.C Area |
| Rocks & Min.: 22:1023. |
Heyl, A. & Pearre, N (1965) Copper, zinc, lead, iron cobalt and barite deposits of the Piedmont Upland in Maryland: Maryland Geological Survey: Bulletin 28, 72 p. | |
| Mines of the Washington D.C Area |