Muscovite from Katie Mine, Boulder County Tungsten Mining District, Boulder County, Colorado, USA
USA | |
| [var. Sericite] Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
USA | |
| [var. Sericite] Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |