The Prospect mine is located approximately 4 miles northwest of Ramona, in the SE/4 SE/4 of Section 6, T.13S, R.2E, SBM. A claim to the deposit was made on September 15, 1904, by H. A. Warnock and John P. Sutherland, of Ramona.
The mine was developed by a small open cut made on the east side of the road in Hatfield Canyon. The deposit was described by Kunz as a pegmatite ledge about 6 feet in width, poorly crystallized, with most of the gems being found as "frozen into the ledge"; few pockets were said to have been discovered.
These workings were reported to have produced gem quality spessartite and greenish tourmaline.
References:
Kunz, G. F. 1905. Gems, jeweler's materials, and ornamental stones of California. California State Mining Bureau bulletin 37: p. 150.
Merrill, F. J. H. 1914. Geology and Mineral Resources of San Diego and Imperial Counties: Gems, Lithia Minerals. California State Mining Bureau, San Francisco, Cal. California State Printing Office, December. Chapter 1, page 63.
