Feldspar Group from selected localities.
USA | |
| [var: Perthite] U.S. Geological Survey Professional Paper 297 |
[var: Perthite] U.S. Geological Survey Professional Paper 297 | |
[var: Perthite] USGS Prof Paper 297F | |
| Rocks & Min.: 57:155. |
[var: Perthite] U.S. Geological Survey Professional Paper 297 | |
[var: Perthite] U.S. Geological Survey Professional Paper 297 |