Sten Anders Smeds

Sten Anders Smeds sends greetings from Sweden with two photos of a runic inscription in pegmatite near the village of Kumla, parish of Övergran, Uppsala, Sweden. Sten Anders stands next to the stone, which has been painted to reveal the chiseled marks. The stone bears the inscription: "Gunnhild had these marks made after Tjälve, her son, and after herself. Arbjörn cut this stone." from this Wikipedia entry: https://sv.wikipedia.org/wiki/Upplands_runinskrifter_652

Sten Anders quips “A perfect proof that the pegmatites of south central Sweden crystallized well before AD 1000”, the age of the Vikings.

Figure 1. Sten Anders Smeds - Runsten U 652 Pegmatit Kumla Ӧvergran Socken 1.

Figure 2. Runsten U 652 Pegmatit Kumla Ӧvergran Socken Detail.

(click on a thumbnail for the full-size picture (439 KB)

Richard Bedell, sent in these photos of the 1982 Winnipeg Pegmatite Short Course.

Short Course Images

Rick Kennedy (text added by David London)

Rick Kennedy has shared photos of recent finds of aquamarine and topaz from the California Blue pegmatite mine, located in southwestern San Bernardino County near the city of Yucca Valley, California. The mine is currently owned by a partnership including Rick Kennedy, Ian Merkle, Paul Geffner, Noel DeDora and David Schmidt. Prior to March 7, 2019, it was fully owned by Dave Schmidt. The mine produces gem-quality crystals of aquamarine and topaz. Those pictured here were found in May 2019.

(click on a thumbnail for the full-size picture of the aquamarine (1.5 MB)

(click on a thumbnail for the full-size picture of the topaz (1.3 MB)

Gary Freeman (text added by David London)

Recent underground mining at Mt. Mica, Oxford, County, Maine (USA) by Gary Freeman and Brian Pedersen has produced interesting exposures of the pegmatite. These two photos, offered by Gary Freeman to share with PIGs, show the pegmatite from hanging wall to footwall in the broad view of the cut. Note the footwall portion on the right side of the drift. The gray linear masses, shown in the detailed photo, are upward-branching skeletal quartz crystals. The term "arborescent", meaning "tree-like" in growth or appearance, applies to this habit. I have described upward-branching, multi-meter scale "trees" of skeletal quartz in the lower wall zone of the Tanco mine, Canada. The arborescent quartz "trees" with interstitial albite grew with elongate crystals of K-feldspar, some graphic in habit, of comparable size (e.g., Fig. 6 of London, D. (2018) Reading pegmatites: what quartz and feldspar say. Rocks and Minerals, 93, 320-336). These at Mt. Mica are smaller but no less impressive for the definition of their habit.

PIGs are familiar with graphic granite, the intergrowth of K-feldspar and quartz. In graphic granite, quartz forms large skeletal crystals whose shape and distribution are determined by the morphology along the growth surface of the K-feldspar (Fenn, P.M. (1986) On the origin of graphic granite. American Mineralogist, 71, 325-330). In the case of arborescent quartz, the morphology of quartz is not so constrained by the feldspar surface, but quartz and albite compete for space along the crystallization front. By their nature, skeletal intergrowths of quartz and feldspar are indicative of rapid crystal growth from viscous melt that inhibits the lateral diffusion of ions that is necessary to grow large, monominerallic crystals. In this case, the growth of the skeletal quartz crystals was essentially one-dimensional from the margins toward center.

(click on a thumbnail for the full-size picture of the pegmatite from hanging wall to footwall (10 MB)

(click on a thumbnail for the full-size picture of the Arborescent Quartz detail (7.8 MB)

Dennis Durgin

Durgin’s of Maine
Email: dennis@durginsofmaine.com

An article about striated garnet from Buckfield, Maine (Bailey 1892) describes an occurrence of almandine on Hill #4 in Buckfield. Subsequent to 1902, there was a name change of Hill #4 to Mt. Marie: William Mills bought the property in 1902 and then named his mining company, Mt. Marie Mineral Co., in honor of his wife. Mt. Marie became the formal designation for this hill soon thereafter.

The author of the 1892 article erroneously placed the site in Buckfield (the Buckfield town line is several hundred yards easterly of Mt. Marie), not an unusual error for the era. However, the description of the crystal from the 1892 article matches the ones I found this spring, 2018, to a "T" and leaves little doubt that I have rediscovered the location referenced by the 1892 article. I have never seen any garnets on Mt. Marie that even remotely resemble these "pagoda style" ones (Figure 1). The very small (less than 10' diameter) prospect pit of this "lost location" is shown on the published map for Little Singe Pole Quarries (Cameron et al. 1954) and is just a few yards easterly of the location of my 2017 garnet find/location (the latter is shown on the Cameron map as the western-most pit/feature). The crystals found in 2017 were of the more common form (Figure 2).

• Bayley, W.S. (1892) Striated garnet from Buckfield, Me. American Journal of Science 44, 79-80.

• Cameron, E.N., Larrabee, D.M., McNair, A.H., Page, J.J., Stewart, G.W., and Shainin, V.E. (1954) Pegmatite investigations, 1942-45, New England. U.S. Geological Survey Professional Paper 255, 352 p.

Figure 1. "pagoda style" garnet, Mt. Marie, Paris (near Buckfield), Oxford County, Maine.

Figure 2. garnet of a more common form, Mt. Marie, Paris (near Buckfield), Oxford County, Maine.

(click on a thumbnail for the full-size picture (1.3 and 1.5 MB)

Anthony R. “Tony” Kampf

Curator Emeritus, Mineral Sciences
Natural History Museum of Los Angeles County
900 Exposition Blvd. , Los Angeles , CA 90007
Phone: 213-763-3328; Fax: 213-749-4107
Email: akampf@nhm.org

On a visit to Minas Gerais back in June of 2002, I was fortunate enough to visit the Navegadora (Orozimbo) mine shortly after the excavation of a huge pocket containing very large crystals of quartz and microcline. The most amazing was a wonderful microcline accented by balls of cleavelandite and paired with (yes, the two pieces fit together) an equally remarkable crystal of quartz. At the time, I was told that the entire lot had been purchased by someone from Japan. Apparently, that deal fell through because later that year I was contacted by Lawrence Stoller asking whether our museum might be interested in buying some large crystals from Brazil. (Yes, those same crystals!) Needless to say, I jumped at the chance.

Unfortunately, acquiring the crystals turned out to be the easy step. Finding a way to get a 6-ton (combined) mineral specimen on display has turned out to be much more complicated. I am happy to report that, 16 years after their discovery, these crystals are now on public display (temporarily) at the Los Angeles County Fair. Hopefully, in the future, we will be able to find a way to put them on permanent display.

A brief description of the find and some additional images of the giant crystals are published here:

• HYRŠL, J. (2002) Riesenkristalle aus Brasilien. MineralienWelt, 13 (6), 10.

Figure 1. Tony Kampf with the two pieces now on display at the Los Angeles County Fair.

Figure 2. Kampf at the mine in 2002.

(click on a thumbnail for the full-size picture (1.5 MB)

David London

Gary Freeman of Freeman Resources has posted a long history of mining for gem materials at Mt. Mica, Maine (see http://www.coromotominerals.com/.). More recently, he has developed pegmatite prospects on Plumbago Mountain, near Newry, Oxford County, Maine. One such prospect, named Plumbago North, has revealed crystals of exceptional size. Gary provided this photo of himself in front of a partial remnant and mold of a spodumene crystal. The longest spodumene crystal measured there to date was 11.6 meters.

(click on a thumbnail for the full-size picture (1.5 MB)

David London

Study area of University of Oklahoma's main Bizzell Library, in preparation for the final exam in GEOL 2224: "Introduction to Mineralogy".

With all of the discussion and effort going into new, non-traditional ways of teaching mineralogy, I thought I would share this with all who care.

I acknowledge that I am old-school in my thinking about what a university science course should be. Though I have adapted my course to address changes in the aptitude and preparation of today’s students, the course remains as challenging for the students taking it now as it was for better-prepared students twenty years ago.

I want my students to learn the principles of mineralogy, but more than that, I want them to learn how to learn, and thereby to elevate their academic effort (and, hopefully, reward). Students who are unwilling or unable to dedicate themselves to the necessary extent drop the course; about a quarter of them drop in each class. Each year, though, about a third of the students finally adopt my study recommendations and guides about half-way through the course. These include daily group study, reviewing and re-writing notes, comparing notes with other students, study cards (aka flash cards), and drills on the board from student to student.

The view here is of white boards in the student study section of our main university library. The content on the boards was written by one student in my mineralogy class, in preparation for the final exam. The student set out to write out everything he thought was important from the course, based on what he could remember, and then edited it as he referred back to his notes. It pleases me, and it should please others, to see students, like this one, who try to master the traditional content in traditional ways.

(click on a thumbnail for the full-size picture (1.9 MB)

David London

Every now and then we grow a mineral texture that is as beautiful as it is complex and inexplicable. In this case, we grew plumose mica, starting with Fe-rich mica along its "spine" (brightest BSE signal), and radiating outward into muscovite. The mica spiral is almost entirely encased in a single quartz crystal, as are all micas grown from this series of experiments with the Macusani obsidian. The two together constitute a graphic intergrowth in the central melt pools of the experimental products. The mica cluster to the left of the spiral is probably connected to it, and both micas and quartz are surrounded by glass (quenched melt).

(click on a thumbnail for the full-size picture.)

David London

Text + 3 pictures (pdf - 177 K)

Individual images

Jeffrey E. Patterson (University of Calgary, Southern California Research Station) contributes this tantalizing photo of polychrome tourmaline crystals and the pocket they came from in the Himalaya mine, Mesa Grande, CA. The large crystal on the right measures 8 x 3 cm. The pocket, which was excavated by Jose Montes of Pala International, was located in 1998 by GPR imagery conducted and interpreted by Jeff. J.E. Patterson and J.D. Means have also posted a preliminary GPR survey of the Cryo Genie pegmatite (see PIG Articles), which can be accessed along with other Cryo Genie news at http://home.earthlink.net/~goke/GPR.htm.

(click on a thumbnail for the full-size picture.)

Beauty is in the eye of the beholder, and in addition to pink & blue tourmaline crystals the size of your arm, many PIGs will appreciate this photo from Mark Jacobson, presently in Western Australia. This very fine crystal of euxenite is from the Calcaling pegmatite, in a pegmatite field (newly recognized as NYF-type) named Mukinbudin, Western Australia. The euxenite crystal is 2 cm tall by 0.8 cm wide. It is hosted by albite and crystallized perpendicular to a flat ilmenite plate. Other accessory minerals from the pegmatite include ilmenorutile, monazite, fluorite, and beryl. Mukinbudin is within the Murchison Terrane of the Archaean Yilgarn Craton.

(click on a thumbnail for the full-size picture.)

For those of you who haven’t starting thinking about the upcoming Tucson Gem & Mineral Show, or if you haven’t been able to think of anything else for the past couple of weeks, here are some pegmatite-related photos from mineral dealer and collector Luiz Menezes (Luiz Menezes Minerals). Luiz graciously offered this update on pegmatite material coming out of Brazil. He regards the new find of kosnarite crystals to be most significant; the kosnarite crystals are sharp, up to 3 mm in size, on albite matrix associated with zanazziite, greifensteinite, rockbridgeite, ushkovite, goyazite, amblygonite, eosphorite, fluor-apatite, elbaite and lepidolite. They came from a pegmatite located on the Jenipapo district, Itinga, Minas Gerais, Brazil. Please note that this announcement is offered for information only, and it is not a particular endorsement of this or any other mineral vendor. — David London

Captions

Figure 1. Amblygonite crystal on albite, Telírio mine, Linópolis, Minas Gerais (3 x 3 cm)

Figure 2. Twinned manganotantalite, Alto de Furnas, Equador, Rio Grande do Norte (3.5 x 3.5 x 3.0 cm)(see Mineralogical Record, 33(6), 505-510, 521)

Figure 3. Twinned manganotantalite (3.0 x 2.5 x 1.2 cm ) on quartz, Alto de Furnas, Equador, Rio Grande do Norte (6 x 3 cm )

Figure 4. Twinned cassiterite (2 x 1.5 x 1.5 cm) on albite (5 x 5 cm), Divino das Laranjeiras, Minas Gerais

Figure 5. Gormanite (2.5 x 2.0 cm) on albite (5 x 5 cm), Linópolis, Minas Gerais

Figure 6. Kosnarite (3 mm crystals) on albite (4 x 3 cm), Jenipapo district, Itinga, Minas Gerais

Figure 7. Greifensteinite (based on preliminary EDS results) or zanazziite (ball-like aggregates, brown color) on greenish muscovite clusters; over the muscovite plates there are white ball-like aggregates of a mineral of the jahnsite-whiteite group (quantitative analyses in progress), Sapucaia pegmatite, Galiléia, Minas Gerais (type locality for frondelite, tavorite, moraesite, faheyite and barbosalite)

Figure 8. Beryllonite, contact twin (1.5 x 1.5 cm), Telírio mine, Linópolis, Minas Gerais

Figure 9. Twinned ferrotapiolite (5.5 x 4.0 x 3.0 cm), Sapucaia district, Divino das Laranjeiras, Minas Gerais.

Individual images

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Spectacular mineral specimens from granitic pegmatites are always available at the Tucson Gem & Mineral Show and satellite shows. This year seemed exceptional only because there was so much pegmatite material available in a wide range of prices. Pakistan and Afghanistan were well represented as usual, but Brazilian mineral specimens, in my opinion, were uncommonly good and plentiful, and new African material was available from a variety of sources. Rare pegmatite minerals, particularly phosphates, Nb-Ta oxides, and baestnesite, were offered by numerous dealers, and minerals of beryllium (beryl, phenakite, euclase, beryllonite, herderite) were everywhere. Even a PIG could go a lifetime without seeing pollucite, but some of the largest, most perfect crystals of pollucite ever found were offered by at least two vendors. If your tastes run more to the rock-forming minerals (and mine do), this was a great year for feldspars and micas. Here are some photos.. — David London

Captions

Figure 1. beryl v. aquamarine, 9.7 kg, found 1995 at Karur, Tamilnadu district, India; courtesy of K.C. Pandey, Superb Minerals India PVT Ltd

Figure 2. zoned beryl, v. morganite rim and aquamarine core, ~ 11 cm dia, Laghman province, Afghanistan; courtesy Kristalle/Crystal Classics

Figure 3. euclase, Last Hope mine, Miami, Zimbabwe; courtesy Kristalle/Crystal Classics (6 x 3 cm )

Figure 4. pollucite, Kandesh, Paprok, Kunar Province, Afghanistan; courtesy Victor Yount

Figure 5. pollucite, Kandesh, Paprok, Kunar Province, Afghanistan; courtesy Rob Lavinsky/Arkenstone

Figure 6. microcline, 20 cm tall, Aracuai district, Minas Gerais, Brazil

Figure 7. microcline, 45 cm wide, Aracuai district, Minas Gerais, Brazil

Figure 8. microcline with aegirine, 33 cm wide, Mt. Malosa, Malawi

Figure 9. albite with epidote, 12 cm wide, Capelinha, Minas Gerais, Brazil

Figure 10. zoned mica on microcline, 10 cm tall, Minas Gerais, Brazil

Figure 11. muscovite with garnet and beryl, ~ 35 cm wide, Pakistan; courtesy Haleem Khan/Hindukush Malala

Figure 12. muscovite street scene

Figure 13. beryl, topaz, tourmaline; courtesy Lucio Alvarez

Figure 14. tourmaline on quartz, ~ 40 cm tall, Minas Gerais, Brazil; courtesy Vasconcelos

Individual images

On the subject of unusual habits for tourmaline (see PIG Comments & Questions), Federico Pezzotta submitted this photo of mineral collector Sarah Sudcovsky holding an exceptional mushroom-shaped tourmaline sample with minor quartz and feldspar. Bill Larson, who presently owns the specimen, reports the locality as Momeik, north of Mogok, Burmah. The Mogok Mineral Tract lies within a central belt of evolved tin-tungsten granites and associated topaz-bearing pegmatites that stretches north-south through the country (Zaw, 1998). Zaw (1998) summarizes the geology of the granitic rocks and provides a good petrologic and geochemical overview of the pegmatites.

Zaw, K. (1998) Geological evolution of selected granitic pegmatites in Myanmar (Burma): constraints from regional setting, lithology, and fluid-inclusion studies. International Geology Review, 40 (7), 647-662.

Captions

Figure 1. Tourmaline mushroom

Figure 2. Tourmaline mushroom detail

Individual images

It has taken great restraint not to litter the PIG site with photos or other cute images of pigs (the four-legged kind: pigs, not PIGs). This photomicrograph from Jeffrey Patterson, however, is irresistible. The photomicrograph (cross-polars, 2.5 mm width) shows a quartz "pig" found in a sandstone that hosts pegmatites in Madagascar. The sample was collected by Jeffrey Patterson during the Madagascar pegmatite symposium in 2001 (see field guide by Federico Pezzotta in the PIG Articles).

Individual images

Weighing in at 105 kg, this amazonite crystal from Brazil (Fig. 1) was neither the biggest nor the best that Irene Ching of Bolva Group Inc. had to offer at Tucson 2004, but it was impressive enough. All the crystals from this particular locality (details not known or given) had a selective coating of black tourmaline on one face (Fig. 2). - David London

Individual images

Dr. Jacques Patureau of Argentat, France, sent me these photos and brief text of pegmatite locations near the areas of Chabanne and Limousin, Central Massif, west of Clermont-Ferrand, France. The photos are striking, and the beauty and complexity of the textures were unexpected, at least by me. Dr. Patureau has graciously authorized me to post these photos on the PIG site, with brief captions. Any comments or questions can be addressed back to Dr. Patureau at patureau.jp@wanadoo.fr

This lenticular pegmatite was exploited for K-feldspar and piezoelectric smoky quartz crystals (up to 100 kilos). Common minerals: apatite, triplite, zwieselite, beryl, niobo-tantalite, autunite, torbernite. This zoned pegmatite with Be, Nb, Ta and Zr is embedded in an orthoclase leucogranite (granite with two micas) exhibiting a poorly marked alkaline trend of the Variscan chain (Carboniferous).

Figure Margnac 1 represents a K-feldspar (perthitic microcline), rimmed by radial (curved) muscovite and then, on selected faces, radial platy albite (clevelandite), at the margin of the block microcline intermediate zone and the quartz core of the pegmatite. Quartz within the core reportedly contains hydrocarbon inclusions.

This more or less lenticular pegmatite was exploited for K-feldspar and beryl. Common minerals: beryl, apatite, triplite, topaze, amblygonite and turquoise, cassiterite, niobo-tantalite, autunite, torbernite. This potassic pegmatite with beryl is (locally) strongly albititic (Li, Ta, Nb are associated with albite) and exhibits a significant quartz core. It is embedded in a microcline leucogranite of Variscan age.

Figure Chabanne 2 represents a contact between the granite and a pegmatite. The contact is denoted by zoned (layered) aplite.

Figure Chabanne 3 represents a quartz core of grey to black colour in the centre and pinkish on the edges. The cracks of the quartz contain torbernite. These were the first uraniferous indicators found in the region (24,630 t of uranium were afterwards exploited from this region). The albitic portions contains amblygonite, niobo-tantalites, stannous tantalite, and topaz.

Individual images