The Pegmatite Interest Group (PIG)

Are you interested in pegmatites? The Pegmatite Interest Group (PIG) is comprised of individuals who share a fascination with and appreciation of the mineralogy and petrology of pegmatites. 

MSA-pegmatite – The Pegmatite Special Interest group has a listserv to pass on information about Pegmatite activities. The MSA-pegmatite Listserv is an announce-only list serve. It is not set up to allow members to send messages. 

A list of relevant pegmatite websites.


Royal Geological Society of Cornwall, at www.geologycornwall.com, is a new website on a famous old collecting site: the granites, pegmatites, and ore-bearing veins of Cornwall, UK.


DAKOTA MATRIX. The Black Hills pegmatites site by Tom Loomis includes two very interesting and contemporary articles about pegmatite mines in the Black Hills, South Dakota. Dakota Matrix also has its MineralPedia, an illustrated alphabetical listing of the minerals combined with short descriptions the mineral’s properties, the origin of its name, as well as geographic and geologic occurrences.


Gary Freeman (Coromoto Minerals) maintains an attractive and informative pegmatite website (http://www.coromotominerals.com/index.html) that details mining at the Orchard and GE pegmatite quarries in Oxford County, Maine. The site features photo galleries of some of the best specimens from five years of mining, and there are maps, views, and text that depict the geology and show the history of mining over time.

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Tomáš Kadlec (tomas.kadlec@vinci-construction.com) has offered four URL links to the geology, chemistry, and photos of pegmatites in Golčova Jeníkova, Moldanubikum, Czech Republic. These include analyses of tourmaline and garnet, and morphological features of etched garnets.

Geology: https://www.mineralogist.cz/anatas-a-rutil-z-dutinoveho-pegmatitu-u-golcova-jenikova

Chemistry: https://www.mineralogist.cz/chemismus-dutinovych-turmalinu-a-granatu-z-pegmatitu-u-golcova-jenikova

Garnets: https://www.mineralogist.cz/krystaly-granatu-z-dutinoveho-pegmatitu-od-golcova-jenikova

Almandine: https://www.mineralogist.cz/golcuv-jenikov-almandin

Two other discussions on etched and unetched garnets are posted in the “Short Articles” folder on the PIG site.

Compilation of book, chapter, article, abstract, or completed dissertation or thesis references on the topic of pegmatites and their minerals, starting 1 January 2013.


Hog Holler 01 Jan – 30 Jun 2013 (56.7 KB).

Hog Holler 01 Jul – 31 Dec 2013 (76.5 KB).

Hog Holler Jan – Dec 2014 (75.3 KB).

Hog Holler Jan – Dec 2015 (106.5 KB).

Hog Holler for 2021 (80 KB).

Hog_Holler_2022

Georef 2023 part 1

Georef 2023 part 2


If you published (including DOI in press) a book, chapter, article, abstract, or completed a dissertation or thesis on the topic of pegmatites and their minerals, please send me a complete citation to that work. Please include works only that are accessible through GeoRef, GeoscienceWorld, or ScienceDirect (dissertations are indexed by all, but I’m not sure all M.S. theses are; so, go ahead and send citations for M.S. theses including all of the institutional information that one would need to request a copy).

Read questions and answers about pegmatites below. Submit your own comments, questions or replies.


1. What would cause corrosion of some minerals in one portion of the pegmatite while in other areas of the same pegmatite minerals show little or no corrosion? To Find Out Click Here


2. White overgrowths on amazonite – albite or microcline? To Find Out Click Here


3. Vapour saturation in pegmatite – when does it take place and what is the evidence? To Find Out Click Here


4. Pegmatite crystallization – an open or closed system? Can it be open to influx of metamorphic/meteoric fluid from external sources, and at what stage? What is the evidence of pegmatite becoming open to the influx from external system(s)? To Find Out Click Here


5. To what extent is replacement a valid late-stage process within pegmatites? If it is, in particular for “albitization” (replacement of K-spar by albite), then what is the disposition of the K that must be displaced by the Na? To Find Out Click Here


6. A series of questions that pertain to the fractionation trends among the (Mn,Fe)(Nb,Ta) oxides in pegmatites. In general, these oxides exhibit increasing Mn/Fe and Ta/Nb with progressive fractionation. Comments on several factors ­ including solubility with temperature, effects of co-crystallizing phases, and the selectivity of the Nb and Ta oxide structures ­ that might influence this trend. To Find Out Click Here

Mount Mica Discovery

Gary Freeman began mining pegmatite at Mount Mica, Maine, in August of 2003. For a number of years, he posted mine information and updates of mineral finds on his website http://www.coromotominerals.com/. That mining history with illustrations through 2008 remains on line. However, Gary’s mining has continued ever since with Brian Pedersen. In the course of their more recent work, they have encountered pockets containing lepidolite and polychrome tourmaline for which the mine is renown. However, a recent large pocket proved exceptional on January 3, 2019. This video, taken by Brian Pedersen and provided by Gary Freeman, shows Gary’s wife, Mary, extracting a large and brilliantly blue-green tourmaline. Their exploration of the large pocket continues.

Essays on the Study of Pegmatites is a series of informal articles that present my comments on historical papers in this field. Most of the publications would be familiar to anyone who has studied the literature of pegmatites. A few of the articles are obscure, but they have contributed in some important way to my own understanding. My goal is to extract the significant content that each article contains and discuss it in the context of the informal essay. I will seek to make clear why each paper is worthy of a detailed read. Some of that information is factual, some conceptual, and some inferential, by which I mean the sometimes veiled messages of some authors that gave me insight into their thoughts. Most of the historical works are not well known nor readily accessible to the many amateur scientists, graduate students, miners, mineral collectors, and other aficionados of pegmatites who follow the PIG webpage. I will post PDF copies of the papers for which I can get permission. In some cases, I will be able to provide links to purchase articles. Those who have access to interlibrary loan services can acquire most of them in that way..


Essay #1: Cameron et al 1949 Overview

Essay #2: Cameron et al 1949 Zones

Essay #3: Cameron et al 1949 Fracture Replacements

Essay #4: Cameron et al 1949 Origin of Units

Essay #5: Jahns (1953a,b): The Genesis of Pegmatites

Essay #6: Jahns (1955): The Study of Pegmatites with References to Bowen (1928, 1933)

Essay #7: Vlasov (1961): Principles of Classifying Granite Pegmatites, and their Textural-Paragenetic Types

Essay #8: Jahns and Tuttle (1963): Layered Pegmatite-Aplite Intrusives

Essay #9: Jahns and Burnham (1969) Experimental Studies of Pegmatite Genesis

Essay #10: Swanson (1977) and Fenn (1977, 1986): Experimental Studies of Crystallization in the Alkali Feldspar and Granite Systems

Essay #11: David B. Stewart (1978): Petrogenesis of Lithium-rich Pegmatites

Essay #12: Chakoumakos and Lumpkin (1990) Pressure – temperature constraints on the crystallization of the Harding pegmatite, Taos County, New Mexico

Essay #13: Petr Ćerný: The Classification and Tectonic setting of Pegmatites

Contacting PIG – If you have news, notices, comments, or other information to post on this website, please send those in electronic formats only to

Dr. David London
University of Oklahoma
Norman, OK
USA

E-Mail: dlondon@ou.edu