|
USA | |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Henwood, W.J. (1871): Transactions of the Royal Geological Society of Cornwall 8(1), 371-384 |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Koschmann, Albert Herbert, Bergendahl, M.H. (1968) Principal gold-producing districts of the United States. Professional Paper 610. US Geological Survey doi:10.3133/pp610 |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Henwood, W.J. (1871): Transactions of the Royal Geological Society of Cornwall 8(1), 371-384 |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |