New Mexico Mineral Symposium — Abstracts

There are different types of types. As defined by Dunn and Mandarino in 1987, a holotype is that single specimen used to determine the original description of a proposed new mineral. All data used in the description must have been derived from this single specimen. If more than one specimen from the type locality (where the new mineral was first discovered) was used to describe a new species, then these additional specimens are called cotypes. Cotypes are used to confirm any additional measurable data. Unfortunately, examining the specimen visually doesn’t count. And then there are neotypes. This is mineral material from the type locality used to re-examine and possibly redefine a mineral when the holotype or cotype can’t be found. In 1970, Embrey and Hey first proposed a system of “types” for minerals. Four other “types” were included in their proposal, but the three mentioned above are those used most frequently.

Of the more than 4,000 known minerals, 88 are Arizona type minerals. They were first discovered and described within the state of Arizona. Of those 88, four have been discredited, proven to be variations of known species. These four are arizonite, bisbeeite, cliftonite, and duhamelite.

Minerals receive their names by various means, but it is the discoverer/describer who determines what that name will be. Then it must be approved by the Commission on New Minerals and Mineral Names and the Commission on Museums of the International Mineralogical Association. Minerals are named after places, in particular, the place where they were discovered. Of Arizona’s 88 type specimens (including those discredited), 23 are named after places. Minerals are named after individuals (often times, after the discoverer) or groups of people. Fifty-three of Arizona’s type minerals are named after people. And finally, minerals are named after some physical or chemical property. There are 12 such minerals on the list of Arizona’s types.

The Permanent Mineral Collection (PMC) in the Earth Sciences Center (ESC) at the Arizona–Sonora Desert Museum (ASDM) has 53 of Arizona’s type minerals, two of which are discredited species—bisbeeite and duhamelite. All but two are from the type localities but not the holotypes. Specimens of emmonsite and discredited duhamelite are from Sonora. The ASDM does have a cotype of shattuckite from the type locality in Bisbee, though, in the PMC.

The goal of the ESC at the ASDM is to acquire examples of all of Arizona’s type minerals, preferably from the type localities, and to compile a catalog that will include the mineral name and how that name was derived, its chemical and physical description, the type locality, an image of the mineral, and a hard copy of the published citation.

References:

1. Anthony, J. W., Williams, S. A., Wilson, W. E., and Grant, R. W., 1995, Mineralogy of Arizona, 3rd edition.
2. Arizona???Sonora Desert Museum Earth Sciences Center???s permanent mineral collection and catalog.
3. Commission on Museums of the International Mineralogical Association web site.
4. Commission on New Minerals and Mineral Names web site.
5. Dunn, P. J., and Mandarino, J. A., 1987, Formal definitions of type mineral specimens: American Mineralogist, v. 72, pp. 1269???1270.
6. Embrey, P. G., and Hey, M. H., 1970, ???Type??? specimens in mineralogy: Mineralogical Record, v. 1, no. 3, pp. 102???104.