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Mineral Specimens with Ettringite
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3 major crystals dominate the top of this matrix plate of hausmannite, smothered by a soft carpet of oyelite. The two frontal crystals are 4 cm long, and a 5-cm crystal runs under them, linking them all together in a chain of color. A larger, fatter , broken-off crystal is a backstop at the base of the cluster. Overall this is a dramatic piece, particularly shown in the vertical, and it is more ettringite than one normally sees on one specimen!
A truly outstanding, lemon yellow crystal measuring 4 x 1.7 x 1.5 cm, perched against a matrix of hausmannite, makes for one of the more impactful and memorable miniatures in this lot. The black on yellow color contrast is REALLY stark and exciting, and I think overall the balance of the two species makes the piece special. Pristine, complete all around, this is a competition grade miniature
Only a very few specimens in this pocket seem to have caught the nearby hematite crystals, and come out in association. This piece is dramatic! It features a doubly-terminated 4.4-cm crystal, inset with a small cluster of glistening jet black hausmannite, ON the hematite-covered plate. On the other side, it is covered by soft white oyelite, so either side offers great contrast for the display of the specimen. The hematites, to 1.7 cm, are mirror-bright, so shiny and reflective you can shave in them. This is a unique piece from a unique pocket, with singular aesthetics.
A cute, 3.6-cm-tall crystal perched nicely on a little shard of manganese gossan matrix, makes this a fine miniature in a good price range. The crystal is lemon yellow, translucent, and complete all around, an excellent example of this style and pocket
A cute, 3.9-cm-tall crystal : it is lemon yellow, translucent, and complete all around save a small contact near the base in rear, overall an excellent example of this style and pocket
This is a huge specimen, with more ettringite in one place than I have ever seen. It is really subtle in its beauty, with oyelite between the cracks in the crystals, providing a white webwork background on which the powder-lemon-yellow crystals stand out all the more dramatically. There is some damage to the edges of the large crystal cluster, where peripheral-facing tips are missing or there is a contact point. But the core clustre is very 3-dimensional, gemmy, and capped by the best terminated crystal: The large crystal in the middle is 10 cm tall, and has a freestanding termination. Charlesite is a close relative of sturmanite and ettringite, and my understanding is that most crystals of either of the two yellow and more common species are actually zoned, and are thus partial charlesite. However, this crystal seems to have a pure, clear core which i suspect is charlesite, perhaps pure. (not analysed). Unusual, in any case! Even more than on other specimens in this lot, many crystals here appear to consist of a white charlesite crystal with an outer layer of powdery-lemon-yellow ettringite atop, from what i am given to understand about how these species form in a related series. The outer layer of colored ettringite is very thin, under 1 mm, and most of this crystal is therefore clear and colorless. These larger crystals (but not the smaller ones) are slightly etched and matte compared to other crystals in this pocket, perhaps part of the phenomena revealing the clear cores. I am sure all in this pocket are zoned in some degree to charlesite and/or sturmanite; but this one is distinctly different, with the totally clear core showing so nicely. A MUSEUM PIECE, in both size and visual impact, even for the public who will not care about the fascinating chemistry revealed here in a gigantic specimen of a very rare species. The backside of the specimen has hausmannite, hematite, and oyelite. 1.3 kilos.
Well-crystallized ettringites are uncommon in the first place, but this specimen is notable for the fact that it is a MATRIX specimen (so many are standalone crystals). It features a sharp, bright yellow, complete and terminated crystal measuring one centimeter in each direction, perched atop the matrix.
Charlesite is a close relative of ettringite – and this specimen (as the Scott Williams label describes) appears to consist of (white) charlesite crystals with an outer layer of bright yellow ettringite. The crystals measure to one centimeter. You would guess the type locality for charlesite to be somewhere in the Kalahari Manganese Fields, but strangely, it is New Jersey; it wasn’t described until 1983. These crystals are nicely isolated on the dark contrasting matrix. Ex Collection of Scott Williams, also with another dealer label (priced $250).
This crystal is a doubly-terminated floater, complete all around, and obviously LEMON yellow, the top color. It is sharply hexagonal and just plain striking. From finds in the early 1980s. I cnanot emphasize how impressive this piece is. AND HOW PRISTINE...
This somewhat gemmy, translucent crystal is exceptional becaus eyou seldome see LARGER ettringites of this size that have such gemmines,s and retain sharp form, with lustre as well. I've seen many brown ones, few yellow ones. It is complete all around and pristine save for the fact that (perhaps in heat shock) it perfectly cleaved down the middle in transport home form Charlie's, and so what once was a $7500 specimen is now reduced to $1500 to ensure it sells and gets away from me becaus eit is depressing. but it really LOOKS like a pricier rock and displays dramaticaly. I had it shot at the worst possible angle here to catch the join head-on. IN person, the repair is really NOT ovbvious at all, and this remains a significant , rare, and beautiful specimen.
A bright lemon-yellow specimen consisting of 2-4mm ettringite crystals perched on a thin shard of matrix, VERY much more 3-dimensional in person!
A beautiful large combination specimen of pastel yellow ettringite perched like sprinkles on rounded aggregates of brucite crystals. I think the blue brucite from this mine is highly unappreciated, and frankly undervalued.
6.0 x 4.2 x 2.4 cm. A relatively large, super-bright and flashy yellow plate of the rare sulfate ettringite, from the prime locality in the Kalahari Manganese fields, where it formed as a precipitate from hydrothermal solutions. New finds at the Wessels mine produced these colorful plates!
5.1 x 2.9 x 1.8 cm. Dazzling coating of gemmy microcrystals of Ettringite on well-terminated calcite crystals. The color and luster of the Ettringite is about as brilliant as you will find.
6.2 x 3.8 x 1.0 cm. Beautiful neon yellow ettringite crystals liberally sprinkled on a plate of crystallized sharp calcite scalenohedra.
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Rob Lavinsky, rob@irocks.com
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share specimen![Ettringite on Oyelite with Hausmannite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-90mm_0610.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-90mm_0610.jpg)
![Ettringite on Oyelite with Hausmannite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-90mm_0611.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-90mm_0611.jpg)
![Ettringite with Hausmannite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-45mm_0646.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-45mm_0646.jpg)
![Ettringite with Hausmannite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-45mm_0647.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-45mm_0647.jpg)
![Ettringite with Hematite and Calcite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-95mm_0642.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-95mm_0642.jpg)
![Ettringite with Hematite and Calcite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-95mm_0634.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-95mm_0634.jpg)
![Ettringite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-40mm_0687.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-40mm_0687.jpg)
![Ettringite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-40mm_0685.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-40mm_0685.jpg)
![Ettringite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-39mm_0697.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-39mm_0697.jpg)
![Ettringite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-205mm_0591.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-205mm_0591.jpg)
![Ettringite from Nchwaning Mines, Kalahari Fields, South Africa [db_pics/new2010/Ettringite-Kalahari-Namibia-205mm_0586.jpg]](db_pics/new2010/Ettringite-Kalahari-Namibia-205mm_0586.jpg)
![Ettringite (matrix!) from N’Chwaning Mine, Northern Cape Province, Republic of South Africa [db_pics/pics/jmix07-152a.jpg]](db_pics/pics/jmix07-152a.jpg)
![Ettringite (matrix!) from N’Chwaning Mine, Northern Cape Province, Republic of South Africa [db_pics/pics/jmix07-152b.jpg]](db_pics/pics/jmix07-152b.jpg)
![Ettringite (matrix!) from N’Chwaning Mine, Northern Cape Province, Republic of South Africa [db_pics/pics/jmix07-152c.jpg]](db_pics/pics/jmix07-152c.jpg)
![Charlesite with Ettringite from N’Chwaning II Mine, Kalahari Manganese Fields, Northern Cape Province, South Africa [db_pics/pics/jmix07-166a.jpg]](db_pics/pics/jmix07-166a.jpg)
![Charlesite with Ettringite from N’Chwaning II Mine, Kalahari Manganese Fields, Northern Cape Province, South Africa [db_pics/pics/jmix07-166b.jpg]](db_pics/pics/jmix07-166b.jpg)
![Charlesite with Ettringite from N’Chwaning II Mine, Kalahari Manganese Fields, Northern Cape Province, South Africa [db_pics/pics/jmix07-166c.jpg]](db_pics/pics/jmix07-166c.jpg)
![Ettringite (floater!) from NChwaning II Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k220a.jpg]](db_pics/pics/k220a.jpg)
![Ettringite (floater!) from NChwaning II Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k220b.jpg]](db_pics/pics/k220b.jpg)
![Ettringite from NChwaning II Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k222a.jpg]](db_pics/pics/k222a.jpg)
![Ettringite from NChwaning II Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k222b.jpg]](db_pics/pics/k222b.jpg)
![Ettringite from NChwaning II Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k228a.jpg]](db_pics/pics/k228a.jpg)
![Ettringite from NChwaning II Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k228b.jpg]](db_pics/pics/k228b.jpg)
![Ettringite on Brucite from Wessels Mine, Kalahari Manganese Fields, South Africa [db_pics/pics/k279a.jpg]](db_pics/pics/k279a.jpg)
![Ettringite from Wessels Mine (Wessel's Mine), Hotazel, Kalahari manganese fields, Northern Cape Province, South Africa [db_pics/mdpics/MD-113497a.jpg]](db_pics/mdpics/MD-113497a.jpg)
![Ettringite, Calcite from Wessels Mine (Wessel's Mine), Hotazel, Kalahari manganese fields, Northern Cape Province, South Africa [db_pics/mdpics/MD-117511a.jpg]](db_pics/mdpics/MD-117511a.jpg)
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