|
USA | |
| Nicolay & Stone (1967), Rocks & Minerals: A Guide For Collectors of the Eastern US, p.196 |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Nicolay & Stone (1967), Rocks & Minerals: A Guide For Collectors of the Eastern US, p.196 |
| (1917) Useful minerals of the United States. Bulletin Vol. 624. US Geological Survey doi:10.3133/b624 USGS McKenzie Formation and Clinton Group |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Zeitner, June Culp (1968) Appalachian Mineral & Gem Trails. Lapidary Journal, Inc. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Zeitner, June Culp (1968) Appalachian Mineral & Gem Trails. Lapidary Journal, Inc. |
| Nicolay & Stone (1967), Rocks & Minerals: A Guide For Collectors of the Eastern US, p.197 |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Nicolay & Stone (1967), Rocks & Minerals: A Guide For Collectors of the Eastern US, p.196 |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (1917) Useful minerals of the United States. Bulletin Vol. 624. US Geological Survey doi:10.3133/b624 |
| (1917) Useful minerals of the United States. Bulletin Vol. 624. US Geological Survey doi:10.3133/b624 |
| (1917) Useful minerals of the United States. Bulletin Vol. 624. US Geological Survey doi:10.3133/b624 USGS McKenzie Formation and Clinton Group |
| Frank C. Schrader.,Ralph W. Stone and Samuel Sanford (1917) Useful Minerals of the United States USGS Bulletin 624 |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |