Amethyst from
USA | |
| Ferguson, H.G. (1927) Geology and Ore Deposits of the Mogollon Mining District, New Mexico. U.S. Geological Survey Bulletin 787. |
| home.flash.net (2004) http://home.flash.net/~summit1/collect/archive/9704/collect.htm |
New Mexico Bureau of Geology Mineral Museum no. 16564 |
Mule Creek, Steeple Rock Mining District, Grant County, New Mexico, USA