|
USA | |
| Johnson, 1960. Source Book for the Rock & Mineral Collector. |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Earth Treasures Vol 4, Allan W. Eckert, 1987 |
| Johnson, Source Book for the Rock & Mineral Collector, 1960 |
| Johnson, 1960. Source Book for the Rock & Mineral Collector. |
| Rocks & Minerals (1955) 30:371 |
| Dorothy M. Schlegal (1957) Gem Stones of the United States USGS Bulletin 1042-G |
| Ransom, Jay Ellis (1974) Gems and Minerals of America - A Guide to Rock Collecting. Harper & Row. |
| Ransom, Jay Ellis (1974) Gems and Minerals of America - A Guide to Rock Collecting. Harper & Row. |
| Dorothy M. Schlegal (1957) Gem Stones of the United States USGS Bulletin 1042-G |
| Ransom, Jay Ellis (1974) Gems and Minerals of America - A Guide to Rock Collecting. Harper & Row. |