Muscovite from Pitkin County, Colorado, USA
USA | |
| [var. Sericite] Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
[var. Illite] Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. | |
| Austin F. Rogers (1946) Braunite from Snowmass, Pitkin county, Colorado. American Mineralogist, 31, 561-568. |