Biotite from La Plata County, Colorado, USA
USA | |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
| Summerlin, E. (2014). PGE mineralization at the Allard stock: Implications for the porphyry to epithermal transition, La Plata Mountains, Colorado (Auburn University MS thesis). |