Geological Society of America

T263 Gem Minerals, Localities and Geological Significance (Posters)

Wednesday, 25 September 2024
8:00 AM - 5:30 PM
Hall D

THE LITERATURE OF GEM GRANITIC PEGMATITES: CELEBRATING 40 YEARS OF THE GEO-LITERARY SOCIETY

Paper number: T263-7
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Dona Dirlam Presenting Author
Geo-Literary Society, Carlsbad, CA
Barbara Dutrow
Louisiana State University, Baton Rouge, LA
Michael Menzies
Calgary, AB
James Shigley
Gemological Inst. of America (Research), Carlsbad, CA
William (Skip) Simmons
Maine Mineral & Gem Museum, Bethel, ME
Michael Wise
Smithsonian Institution, Washington, DC
Karen Webber
Maine Mineral & Gem Museum, Bethel, ME
Orasa Weldon
OW Design, Tucson, AZ
Brendan M. Laurs
Gem-A, Encinitas, CA

Abstract

Pegmatites, earth’s most magnificent rocks, have been recognized for their unique textures for hundreds of years. The word pegmatite from the Greek word (pēgnymi) which means to bind together refers to the interlocking crystals of varying sizes. Many of the world’s finest mineral specimens and gemstones form from pegmatites. This contribution traces the history of the term’s use. Pegmatites are found on every continent as illustrated by a distribution map. A table will list the prominent gem minerals found in pegmatites. Two QR codes will take readers to the Geo-Literary Society web page and the extensive pegmatite bibliography created by Dr. James Shigley of the Gemological institute of America (GIA).

The early literature of pegmatites can be traced to René Just Haüy, (1743-1822) a French priest and mineralogist. He is credited with the first use of the term granite graphique (graphic granite- an important texture term for pegmatites) to describe granites in his 1801 work Traite de Mineralogie, Vol. 4, p. 304. The term pegmatite in reference to Haüy’s granite graphique first appeared in Alexandre Brongiart’s (1770-1847) Essai d’une classification minéralogique des roches mélangés, 1813, p. 32. Wilhelm Karl Ritter von Haidinger (1795-1871) an Austrian mineralogist and geologist, used pegmatite correctly in his work Handbuch der Bestimmenden Mineralogie....from 1845, p. 585.

The Geo-Literary Society was founded in February 1984 at the Tucson, Arizona Gem and Mineral Show where a group of notable mineral and gem enthusiasts created a new organization. It is dedicated to exchanging information on the geo-sciences and providing a forum for collaboration. This year marks the 40th anniversary of the society. At its February lecture and book signing celebration, it launched its new website, geoliterarysociety.org where Dr. James Shigley introduced an extensive gem pegmatite bibliography. William (Skip) Simmons, Dr. Karen Webber, and Dr. Michael Menzies and Jeffrey Scovil autographed copies of Pegmatology 2nd edition and Pegmatites and Their Gem Minerals. Reviewing the current theories of the origin of pegmatites (fractional crystallization and anatexis) at GSA 2024 further celebrates the 40th year of the work of this society.

Geological Society of America Abstracts with Programs. Vol. 56, No. 5

doi: 10.1130/abs/2024AM-404259

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