Sapphire from Great Plains Domain, North America Plate
USA | |
| Collectively: Behre, et al (1936) Dana 6:1089 Rocks & Min.:58:153-155. |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
| Eckel, Edwin Butt , Cobban, Robert R., Mosburg, Shirley K., Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. |
Calumet Mine, Turret Mining District, Chaffee County, Colorado, USA