Iron from San Diego County, California, USA
USA | |
| Schaller, W. T. (1911d), Orbicular gabbro from Pala, San Diego County, California: Amer. Chem. Soc. Jour., vol. 33, p. 162-166. |
| Kunz, George F. (1905) Gems, Jewelers' Materials, and Ornamental Stones of California. Bulletin 37 (2nd ed.) California State Mining Bureau |