New Mexico Mineral Symposium — Abstracts

A deposit of rare red beryl (bixbite) crystals has recently been discovered near Paramount Canyon in the Black Range, Sierra County, New Mexico. The beryls, sparsely distributed along a small fracture zone in the lithophysal cavities of a pink rhyolite, occur as tabular hexagonal crystals less than 3 mm in diameter and shortened along the c-axis. Small pseudobrookites,hematites, or quartz crystals are commonly perched on the beryl crystals or occur within the same cavity. Hyaline opal is also an associated mineral, and bixbyite, topaz, and cassiterite are present in other nearby rhyolite flows (Fries and others, 1942).

In addition to the New Mexico occurrence, red beryl is found at only two other areas in the world. These sites are in the Thomas and Wah-Wah Mountain Ranges of Utah. At both locations, the bixbite crystals are found as an accessory mineral in rhyolite. A suite of accessory minerals similar to those found in the Black Range of New Mexico occur with the Utah bixbites. Topaz, pseudobrookite, bixbyite, hematite, garnet, and hyaline opal form small, scattered crystals within grey lithophysal rhyolites (Palache, 1934).

Although numerous studies have been undertaken concerning the mineralogy of the rhyolites in the Taylor Creek district of the Black Range, none have ever reported the presence of red beryl as an accessory mineral in the rhyolite. Experimental data collected on bixbite from the other two U.S. localities seem to indicate that the red coloration is due primarily to high concentrations of Mn²⁺ within the beryl (Nassau and other, 1968).

Several deposits of gem and specimen-grade red beryls are presently being mined on a small scale from the rhyolites of the Wah-Wah Mountains and the Thomas Range. The Black Range bixbite locality, presently under claim by the Virgin Mining Company of Socorro, New Mexico, is being evaluated for quality red beryls. Currently, no gem-grade beryls have been discovered at the site, and no bixbite crystals have exceeded 3 mm in diameter. Continued operations may yield larger crystals of the mineral. For those interested in obtaining further information, write Virgin Mining Company, P.O. Box 2439, Campus Station, Socorro, N.M. 87801.

References:

1. Fries, C., Glass, J.J., and Sheller, W.T., 1942, Bixbyite and pseudobrookite from the tin-bearing rhyolite of the Black Range, New Mexico: American Mineralogist, v.27, p. 305-322.
2. Nassau, K., and Wood, D.L., 1968, An examination of red beryl from Utah: American Mineralogist, v. 53, p. 801-806
3. Palache, C., 1934, Minerals from Topaz Mountain, Utah: American Mineralogist, v. 19, p. 14-15