Orthoclase from Maryland, USA
USA | |
| USGS Bull. 426 |
| Pearre and Heyl (1965) |
| reported by Ostrander and Price(1940) but not seen in in dumps by Bernstein (1980) |
| USGS Bull. 426 |
| Beard, R. (2015) Rockhounding Delaware, Maryland, and the Washington, DC Metro Area |
| Rocks & Min.: 11: 8-9. |