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USA | |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| Pearl, Richard M. (1958) Colorado Gem Trails & Mineral Guide. Sage Books, Chicago, Illinois. |
| (2005) Mineral Resources Data System (MRDS), US Geological Survey. |
| D. Slade collection |
| Muntyan, Barbara, Muntyan, John (1985) Minerals of the Pikes Peak Granite [Colorado]. The Mineralogical Record, 16 (3) 217-230 |
21st Street, Colorado Springs, El Paso County, Colorado, USA