Quartz from Cumberland County, Pennsylvania, USA
USA | |
| Beste, Bob (2005) Location Guide for Rockhounds in the United States (3rd ed.) Vol. 3 - Part III - Ohio through Wyoming. |
| D’Invilliers Mark J. Sigouin, P.G. |
Pennsylvania Geology, The Pennsylvania Geological Survey, October 1970, p.11. | |
| [var. Chalcedony] Lapham & Geyer, 1965. Mineral Collecting in Pennsylvania |
Cumberland County, Pennsylvania, USA