Piemontite from Gunnison County, Colorado, USA
USA | |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
| Larsen, E.S. (1942) Alkalic rocks of Iron Hill, Gunnison County, Colorado. Shorter contributions to general geology, 1941-42. United States Geological Survey Professional Paper 197-A. |