Gypsum from Chester County, Pennsylvania, USA
USA | |
| Lapham & Geyer, 1965. Mineral Collecting in Pennsylvania |
| Mineralogical Record, 25(2),pp:105-120. |
USA | |
| Lapham & Geyer, 1965. Mineral Collecting in Pennsylvania |
| Mineralogical Record, 25(2),pp:105-120. |