Moganite: A New Mineral -- Not!

by Marcus Origlieri

Lithosphere (January 1994); Fallbrook Gem and Mineral Society, Inc.; Fallbrook, CA


The November 1993 issue of National Geographic carried a short piece on a new mineral called moganite. In the article, moganite was described as an abundant new mineral occurring in quartz specimens. Apparently, researchers from the Smithsonian Institution studied quartz samples in the museum's collection and, to their amazement, moganite occurred in almost all of the microcrystalline quartz samples studied.

The National Geographic article made mention of an "obscure German scientific journal" from which the Smithsonian researchers originally learned of moganite. The publication was probably the Neues Jahrbuch für Mineralogie Abhandlungen (Flörke et al. 1984) in which moganite is described as gray, resembling chalcedony, and occurring as nodular masses of intermeshed microscopic fibers with admixed opal and chalcedony. Mineralogically, moganite was determined to be a polymorph of silica, crystallizing in the monoclinic crystal system.

Interestingly, the IMA (International Mineralogical Association) has disapproved the mineral. The X-ray diffraction pattern, as well as other properties of moganite, resemble those of quartz. It is very likely the IMA found that moganite was insufficiently different from quartz to warrant the characterization of a separate species. Thus moganite may be very common; it could, in fact, be chalcedony!

References

Dunn, P. J., et al.;
"New mineral names;" American Mineralogist, 70, pp. 871-881; 1985.

Flörke, O. W., Flörke, U. and Giese, U.;
"Moganite, a new microcrystalline silica-mineral:" Neues Jahrbuch für Mineralogie Abhandlungen, 149, pp. 325-336; 1984.

Flörke, O. W., Jones, J. B. and Schmincke, H. U.;
"A new microcrystalline silica from Gran Canaria;" Zeitschrift für Kristallographie, 143, pp. 156-165; 1976.

Weintraub, Boris;
"Within Common Quartz, a Common New Mineral;" National Geographic, 184:5; 1993.

Copyright © 1994 by Fallbrook Gem and Mineral Society, Inc.

The preceding article was originally published in the January 1994 issue of Lithosphere, the official bulletin of the Fallbrook [California] Gem and Mineral Society, Inc; Richard Busch (Editor).

Permission to reproduce and distribute this material, in whole or in part, for non-commercial purposes, is hereby granted provided the sense or meaning of the material is not changed and the author's notice of copyright is retained.


Last updated: 18 September 2002
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