Chalcedony from San Diego County, California, USA
USA | |
| Jahns, Richard Henry & Wright, Lauren A. (1951), Gem and lithium-bearing pegmatites of the Pala district, San Diego County, California. California Division of Mines Special Report 7-A: p. 31. |
| Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 318. Kunz, George Frederick (1906), Precious stones: Mineral Resources U.S., 1905: 1323-1358 |