Palygorskite from Pennsylvania, USA
USA | |
| Smith, R. C. II (1977) Zinc and lead occurrences in Pennsylvania. Mineral Resource Report M72. Pennsylvania Geological Survey |
| Sloto, Ronald A. (1989) Famous Mineral Localities: The Phoenixville Lead-Silver Mines, Chester County, Pennsylvania. The Mineralogical Record, 20 (5) 369-386 |
| www.jonesgeo.com (2011) http://www.jonesgeo.com/codorus.htm |