Biotite from selected localities.
USA | |
| Alfredo Petrov observations, 18-03-2009 field trip. |
Personally observed by Hershel Friedman. | |
| NY State Museum Bull. Nos. 249-250, Magnetic Iron Deposits of SE NY, Clarke, John M. (Sep-Oct 1921): 91. |
| Alfredo Petrov observations |