The Harding pegmatite--Summary of recent research
Douglas G. Brookins, B. C. Chakoumakos, C. W. Cook, R. C. Ewing, G. P. Landis, and M. E. Register


The Harding pegmatite, located in the western part of the Picuris Range about 30 km southwest of Taos, lies 7 km south east of the Rio Grande Canyon at an altitude of 2,260 m (sec. 29, T23N, R11 E) and is readily accessible from a nearby point on State Highway 75 about 10 km east of Dixon (fig. 1). The locality is unique because it has yielded commercial quantities of beryl, lepidolite, spodumene and microlite over a period of a half a century. It also has become a widely known source of handsome mineral specimens, a provocative locality for scientific studies, and a mine noted for its spectacular exposures of pegmatite. The pegmatite itself is a classic locality and point of controversy for those workers who have addressed the question of the origin of pegmatites (Burnham, 1967; Gresens, 1967; Jahns and Burnham, 1957, 1969).
In 1974, Dr. Arthur Montgomery approached the University of New Mexico with an offer to donate the property to the University so that it might be preserved as one of the State's unusual natural assets. Since that time, the University has leased the property from Dr. Montgomery until the transfer of title could be completed. During the past five years, the University has done the yearly assessment work, modified the mine to insure the safety of the public, retained a caretaker for the mine property, designed and completed a walking tour of the mine's surface workings, established museum and research collections of pegmatite specimens, and supported faculty and students in research programs concerning the pegmatite. The Harding pegmatite is now an integral part of the teaching and research program at the University of New Mexico.
The mine property includes both patented and unpatented claims so that the transfer of the title has required the transfer of federal lands to state lands. The transfer literally has required an "Act of Congress" (Senate Bill 1403). The bill was signed by the President as part of Public Law 95-550 on October 30, 1978. The law requires that: (1) the University make application for conveyance, (2) that the conveyance be made "at the fair market value" of the land, (3) that the University provide satisfactory assurances to the Secretary of Interior that no other valid mining claims exist on the transferred lands, and (4) that necessary land surveys be completed. Even with the transfer of title, the United States retains the right to mine strategic minerals should it become necessary for the security of the United States. All royalties from such mining would go to the United States. The faculty of the Department of Geology are indebted to Dr. Montgomery and to the University of New Mexico for their time, resources and patience during this complicated process.
The University plans to make this classic locality continually available for public inspection, study and mineral collecting on a modest scale. During the summer of 1978, well over 500 visitors from over twenty universities and colleges visited the mine. Anyone with an interest in visiting the property should contact the Chairman, Department of Geology, University of New Mexico, 87131 to obtain permission. A splendid collection of representative Harding minerals, donated by Dr. Montgomery, can be viewed in the University's Geology Museum.
This paper is a brief summary of the work of students and faculty of the Geology Department at the University of New Mexico. A more extended discussion of this work may be found in the indicated references. For a detailed discussion of the geology, mineralogy and mining history of the Harding pegmatite see Jahns and Ewing (1976, 1977).


  1. Brookins, Douglas G.; Chakoumakos, B. C.; Cook, C. W.; Ewing, R. C.; Landis, G. P.; Register, M. E., 1979, The Harding pegmatite--Summary of recent research, in: Santa Fe Country, Ingersoll, Raymond V.; Woodward, Lee A.; James, H. L., New Mexico Geological Society, Guidebook, 30th Field Conference, pp. 127-133.

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