Fersmite from Gem Hill, Mesa Grande Mining District, San Diego County, California, USA
USA | |
| Rocks and Mineral: 1998: 168 & 178, Figure 30. |
Foord, Eugene E., Mrose, Mary E. (1978) Rynersonite, Ca(Ta,Nb)2O6, a new mineral from San Diego County, California. American Mineralogist, 63 (7-8) 709-714 |