New Mexico Mineral Symposium — Abstracts

Mention the Magdalena district in Socorro County New Mexico to mineral collectors and, most likely, the Kelly mine with its beautiful aqua botryoidal smithsonite will come to mind. There were, however, more than forty additional mines in the district that produced a wide variety of minerals—many of which are rare and significant in their own right. The presentation, although not all-inclusive, will feature many of the lesser-known mines and minerals of the district.

The mining district got its start in 1877 when Col. J. S. Hutchinson (Old Hutch)first discovered oxidized lead (primarily cerussite) ores in the area. It was smelted in an adobe furnace and the product was hauled to Kansas City by ox teams(Lasky, 1932). Gustav Billing erected a smelter near Socorro in 1881 to handle the ores from the district. It operated until 1893 when it was closed due to the decline of the silver market. The Graphic smelter was erected in 1896 to handle the oxidized lead ores from the district (the three most important mines were the Kelly, Graphic, and Juanita). This smelter operated until 1902 when cerussite was largely exhausted, thus ending the lead carbonate period of the district. The district was revitalized in 1903 with the discovery of zinc carbonate (smithsonite) ore and was especially active during the First World War, reaching its peak in 1916 (Loughlin and Koschmann, 1942). Intermittent mining continued for decades after, but the district never again achieved the production levels of its lead and zinc boom days (Gibbs, 1989).

Mineral collectors visiting the area have generally concentrated on the "big three": The Kelly, Graphic, and Juanita mines. While smithsonite has been the biggest draw, fine specimens of azurite, barite and aurichalcite have also been recovered. Exploration by intrepid collectors of other mines in the district has revealed a surprisingly wide variety of minerals, some of which are new to the district and to the state. Also, looking closely at the "big three": mines has revealed previously ignored or missed minerals of interest. Several of these will be featured in the presentation. We describe these minerals starting from the north end of the district and working to the south.

Anchor mine: This mine consists of a 170-foot decline with three levels. On the second level, wire silver associated with acanthite and galena has been found. The wires were up to one centimeter in length. At the bottom of the decline (adit level) wulfenite and cerussite crystals were recovered. The wulfenite crystals were up to 6mm and the largest cerussite crystal was 3cm (DeMark 2003).

Hardscrabble mine: A strenuous hike reaches the mine, high on a ridge south of the Anchor mine. In June 2008, Rex Nelson and Jim Van Loan collected a blue aqua mineral encrusting rocks in one of the mine’s “glory holes”. XRD analysis confirmed the mineral to be chalcoalumiite, a hydrated copper aluminum sulfate (Lueth, personal communication, 2014). This was the first confirmed occurrence of this mineral in the district and state. Smithsonite, hemimorphite and rosasite can be found on the dumps.

Graphic mine: Aurichalcite specimens are particularly noteworthy as well as azurite. In the 1970’s, many single crystals of azurite up to 2cm were screened from the dumps. Brian Huntsman collected cuprite crystals pseudomorphed by malachite in 1979. Other minerals of note include rosasite spheres on white smithsonite, green “rice-grain” smithsonite crystals and sprays of malachite crystals. Anhedral ilvaite with hedenbergite was found on the dumps in July 1992.

Kelly mine: While much more could be written about the fabulous smithsonite specimens from the Kelly mine, we shall resist! An unusual occurrence in the early 1970s of a botryoidal aqua colored mineral resembling smithsonite was determined to be a compact variety of aurichalcite. However, the attractive specimens, some sprinkled with small rice-grain smithsonite, were limited in number. In 1987, Chris Cowan found small yellow-green dipyramidal crystals of wulfenite on azurite on the 6^th level. This was the first recorded occurrence of wulfenite in the district.

Germany mine: The main adit to the mine is now flooded, but reputedly, thin, tabular crystals of white to pink barite were common.

Juanita mine: Exceptional crystals of golden-brown barite up to 10cm occurred in large pockets in the upper levels. Plattnerite has been found on some of these crystals (first report from this district). Some of the smithsonite has a distinctive yellow-green color. Marvelous micro crystals have been collected from the dumps, including dundasite, azurite, cuprite, malachite after cuprite, and fraipontite. Allophane specimens, colored blue by copper, were once common on the dumps, and can still occasionally be found.

South Juanita mine: Adit level entry to the mine is no longer possible due to collapse and burial of the portal, however the vertical shaft is still open. Mark Massis discovered wonderful specimens of acicular cerussite on drusy azurite in a seam/pocket on the second level of the mine. Only a few specimens were recovered, but a large number of loose crystals up to 2cm were collected. Crinoid stems replaced by smithsonite have also been found.

Black Cloud mine: Recent investigations of this mine, which is accessed by several adits, has not revealed any minerals of interest to the collector. Rosasite has been collected from the Helen Cross group, adjacent to the Black Cloud mine.

Mistletoe mine: In May 1993, dipyramidal and tabular crystals of orange colored wulfenite to 4mm were collected from the mine that is located south and below the Black Cloud mine. Cerussite and jarosite crystals have also been found here.

Enterprise mine: The underground workings of the Enterprise are no longer accessible, but in November 1991, Will Moats collected white rice-grain smithsonite, and Mike Sanders collected finely crystallized aurichalcite from this location. Today, gray smithsonite, jarosite, azurite, aurichalcite coated by calcite, galena and sphalerite can be found on the dumps.

Young America mine: Further south and below the Enterprise mine, the Young America mine is accessible through an adit. Barite crystals line a large pocket (about five feet wide by six feet deep and two feet high). The crystals are thin, tabular, white and have a dull luster. Some occur on drusy quartz. Drusy azurite with malachite is found in another large pocket and Mike Sanders collected some fine specimens of clear rice-grain smithsonite on hematite-covered quartz back in 1998.

Linchburg mine: This mine was extensively explored by Chris DeWitt and one of the authors (RSD) in 1993 prior to its use as a test facility for storing munitions in underground mines. This was a joint venture between the U.S. Corps of Engineers and the Republic of Korea. The development plan called for up to 32 blasts with the largest explosion using 2.5 tons of dynamite (Defensor Chiefton, June 29 & 30, 1993). Entry to the mine following these tests has not been possible to the authors’ knowledge.

Two mineral species not previously reported/confirmed from New Mexico were found in the spring of 1993. Both these minerals, ktenasite and serpierite, are hydrated copper zinc sulfates. An additional unknown hydrated zinc carbonate sulfate remains to be identified. Quartz pseudomorphs after calcite and fluorite are noteworthy as is the occurrence of wulfenite (one of only three other locations in the district). An unusual sheave-type habit of ferruginous calcite is unique. Exceptional crystals of pyramidal cerussite were found on the dump in July, 1973 along with the district’s first reported occurrence of ilvaite in October, 1980.

Iron Mask mine: A visit to the mine in July 2014 by the authors revealed only the stone foundations of structures, minor dumps and vertical shafts. Some minor barite was found on the dumps. According to the Albuquerque Journal, Sept 2, 2009, “A Magdalena man was found dead at the bottom of a 65-foot mine shaft (Iron Mask mine) in Patterson canyon…” We do not recommend rappelling down this shaft!

Undoubtedly there are other unusual mineral species still hidden in the many smaller mines, workings and prospects of the district. Decades of plant growth, erosion, deterioration of the old roads and mine workings, and steep rugged terrain make future mineral collecting both challenging and rewarding.

References:

1. New Mexico Miner and Prospector, 1948, Magdalena Number, vol. 10, no. 8, pp. 1–7.
2. DeMark, R. S. and DeWitt, C. B., 1994, New developments and mineral occurrences at the Linchburg mine, Socorro County, New Mexico: New Mexico Geology, vol. 16, no. 1, pp.15, 16.
3. DeMark, R. S., 2003, Native Silver and Wulfenite at the Anchor mine, Magdalena district, Socorro County, New Mexico: New Mexico Geology, vol. 25, no. 4, pp. 114–119.
4. Eveleth, R. and Lueth, V., 2001, Pseudomorph City—The mineralogical treasures of the Graphic­–Waldo and Kelly mines, Magdalena district, New Mexico: New Mexico Geology, vol. 23, no. 1, p. 21.
5. Gibbs, R. B., 1989, The Magdalena district, Kelly, New Mexico: The Mineralogical Record, vol. 20, no. 1, pp. 13–24.
6. Lasky, S. G., 1932, The ore deposits of Socorro County, New Mexico: New Mexico Bureau of Geology and Mineral Resources, Bulletin No. 8, 139 pp.
7. Loughlin, G. F. and Koschmann, A. H., 1942, Geology and ore deposits of the Magdalena mining district, New Mexico: U.S.G.S. Professional Paper 200, 168 pp.
8. Northrop, S. A., 1959, Minerals of New Mexico, revised, 1996 (Labruzza, F.A.), University of New Mexico Press, 346 pp.