Ruby from Montana, USA
USA | |
Hall, C. (1998) Identifying Gems & Precious Stones (The new compact study guide and identifier). Chartwell Books, Inc., 80 pp. (p. 20). | |
| USGS Bull 269 |
Ransom, Jay Ellis (1974) Gems and Minerals of America - A Guide to Rock Collecting. Harper & Row. | |
| [var. Star Ruby] Gobla, Michael J. (2012) Montana Mineral Locality Index. Rocks & Minerals, 87 (3) 208-240 doi:10.1080/00357529.2012.676825 |
USGS Bull 269 |