Calcite from Berks County, Pennsylvania, USA
USA | |
| Rocks & Minerals (1955) 30:502 Rocks & Min.: 21:278 23:914-915. Rocks & Min.: 21:142-143. |
| Rocks & Min.: 21:278. |
| Rocks & Min.: 17:340. |
| Ref.: Gordon, Samuel G. (1922), Mineralogy of Pennsylvania: 153. |
Pennsylvania Geological Survey (1984, October) Pennsylvania Geology Vol. 15 (5) p2-4 | |
| The Mineralogy of Pennsylvania 1966-1975 Robert C. Smith II, pg. 232, Table 27 |
Econ Geol (1985) 80:418-443 | |
| Smith, R. C. II (1977) Zinc and lead occurrences in Pennsylvania. Mineral Resource Report M72. Pennsylvania Geological Survey |
| Gordon: Mineralogy of Pennsylvania, 1922, p. 159 |
Gordon: Mineralogy of Pennysylvania, 1922 p. 159 |
Dyer Quarry, Gibraltar, Birdsboro, Berks County, Pennsylvania, USA