Milk Opal from USA
USA | |
| Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 282 Lewis, W. Scott (1933), Occurrences of opal in California: Rocks & Minerals: 8: 36-37 |
| NBMG files No. 50600003 Nevada Bureau of Mines and Geology NBMG Open-File Report 96-3 By Stephen B. Castor, Christopher D. Henry, Lisa A. Shevenell |