New Mexico Mineral Symposium — Abstracts

Nature provides a wide variety of green minerals for collectors to choose from: epidote, beryl, uvarovite, microcline, fluorite, brochantite, malachite, and a host of others. However, there is one mineral that seems to stand out in this group: dioptase. The type locality for dioptase is the Altyn-Tyube deposit in Kazakhstan. Worldwide localities include Argentina, Australia, Congo (Zaire), Germany, Mexico, Namibia, New Zealand, Peru, and other countries. In the United States, with one or two exceptions, dioptase is found in the more arid regions of southern California, Nevada, Arizona, and New Mexico. Arizona is the most prolific with approximately 30 localities. Next is Nevada with five and California with three. Dioptase possesses a very distinctive color and crystal form, which, once observed, is usually easy to recognize in the field. Although locations are not numerous around the world, specimens are available through a wide price range, from inexpensive to "off the chart." Most general collections usually contain at least one or two specimens of dioptase.

New Mexico seemingly has been left out of the dioptase picture even though the chemistry of deposits is sometimes similar to localities in other states. In Northrop, Minerals of New Mexico, 3rd rev. ed., 1996, there are two references to dioptase: F. Jones, 1904, at Orogrande, Otero County, and Thorne, 1931, at Santa Rita, Grant County. Both references merely list dioptase as a component in a brief general list of minerals at those mining areas. A check of the collections at New Mexico Tech as well as several private collections of New Mexico collectors fails to turn up specimens from these two localities. In the summer of 2003, in the course of preparing a report on the Old Hadley district, Cookes Peak, Luna County, dioptase was discovered at the Copper mine. This mine also produced the first New Mexico locality for creaseyite in addition to plancheite/shattuckite, fornacite, murdochite, and other species. In September of 2005, dioptase was found on a dump at the Independence lode, Victorio district, Luna County. Dump material produced excellent specimens of dioptase, and subsequent exploration of underground drifts produced three separate areas for additional recovery. Extensive sampling of the underground system produced the following list of minerals: bind- heimite, cerussite, chrysocolla, dioptase, dolomite, duftite, goethite, hematite, hemimorphite, jarosite, malachite, mimetite, mottramite, pyromorphite, quartz, rosasite, smithsonite, stibnite, and willemite. A number of these minerals are new to the Victorio district. The narrow vein of the Independence, completely enclosed in dolomitic rocks, strikes northeast-southwest and dips very steeply to the northwest. The primary ore is, for the most part, completely oxidized. A few remnants of stibnite can still be found in the vein quartz. The ore occurred as irregular pods of dense pale-yellow and blue oxidized stibnite and galena containing values of gold and silver. Secondary minerals such as bindheimite, willemite, pyromorphite, and dioptase are locally abundant, but other minerals are sparse and scattered throughout the mine.

New Mexico is a prime candidate for additional dioptase discoveries. There are several areas in particular that have possibilities. The Florida, Tres Hermanas, and Peloncillo Mountains contain oxidized lead-zinc-copper deposits associated with carbonate rocks necessary for buffering aqueous solutions that provide a favorable environment for the deposition of dioptase. There are certainly many secondary silicate minerals present in the deposits of southern New Mexico. For instance the author has in his collection willemite, a secondary zinc silicate, from 27 localities in Hidalgo, Luna, and Grant Counties. So, keep your eyes open, and you might be the one to discover the next dioptase locality in New Mexico. And that will happen only if you are willing to chase the elusive green goddess.

References:

1. Griswold, G. B., 1961, Mineral deposits of Luna County, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Bulletin 72, 157 pp.
2. Jicha, H. L., Jr., 1954, Geology and mineral deposits of Lake Valley quadrangle, Grant, Luna, and Sierra Counties, New Mexico: New Mexico Bureau of Mines and Mineral Resources, Bulletin 37, 93 pp.
3. Jones, E. A., 1904, New Mexico mines and minerals (World's Fair edition, 1904), being the epitome of the early mining history and resources of New Mexican mines, in the various districts, down to the present; Geology of the ore deposits, complete census of minerals, mineral and irrigation waters, table of altitudes and other general information, Santa Fe.
4. Northrop, S. A., 1996, Minerals of New Mexico, 3rd ed., revised by F. A. LaBruzza: University of New Mexico Press, Albuquerque, 346 pp.
5. Thorne, H. A., 1931, Mining practice at the Chino mines, Nevada Consolidated Copper Company, Santa Rita, New Mexico: U.S. Bureau of Mines, Information Circular 6412, 28 pp.