|
USA | |
| 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 |
| Dorothy M. Schlegal (1957) Gem Stones of the United States USGS Bulletin 1042-G |
| Rob Lavinsky. |
| Self collected by Jennifer Nemitz. |
| www.johnbetts-fineminerals.com (n.d.) http://www.johnbetts-fineminerals.com/jhbnyc/mineralmuseum/picshow.php?id=25387 |
| Collected by James J. "Skip" Colflesh, 2007. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
| Dietrich, R. V. (1990) Minerals of Virginia. Virginia Geological Survey. |
Kirbyville, Berks County, Pennsylvania, USA