Perthite from Providence County, Rhode Island, USA
USA | |
| Rocks & Minerals (1986): 61: 286-289 |
| |
| Barton, W. & C. E. Goldsmith (1968) New England Beryllium investigations. US Bureau Mines RI 7070 |
USA | |
| Rocks & Minerals (1986): 61: 286-289 |
| |
| Barton, W. & C. E. Goldsmith (1968) New England Beryllium investigations. US Bureau Mines RI 7070 |