| Murdoch, Joseph, Webb, Robert W. (1966) Minerals of California, Centennial Volume (1866-1966) - California Division Mines and Geology, Bulletin 189. p.1-559. Schaller, Waldemar Theodore (1911e), Notes on purpurite and heterosite: USGS Bulletin 490: 79 Kunz, George Frederick (1906), Precious stones: Mineral Resources U.S., 1905: 1344 |
Pack Rat Mine, Tule Mountain, Jacumba, San Diego County, California, USA