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John S. White
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Joined: 04 Sep 2006
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Location: Stewartstown, Pennsylvania, USA
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Posted: May 14, 2010 08:13 Post subject: Re: Calcite Forms - (4) |
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These photos of the same piece probably show the poker chip habit better. This is from the Fozichong lead & zinc mine, Guangxi Province, China, and is 11 cm across.
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_________________ John S. White
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Jordi Fabre
Overall coordinator of the Forum
Joined: 07 Aug 2006
Posts: 4902
Location: Barcelona
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Posted: May 28, 2010 04:45 Post subject: Re: Calcite Forms - (4) |
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A funny one
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The white crystals are not what they look like: they are Calcite, so don’t be mistaken! ;-) The brown ones are what they look like: Dolomite... Roata mine, Cavnic, Maramures, Rumania Mined in 2004 Specimen size: 3.5 × 3.4 × 2.9 cm. Calcite fluorescent long & short UV Photo from "Reference Specimens" |
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Jordi Fabre
Overall coordinator of the Forum
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Location: Barcelona
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Posted: Jun 09, 2010 08:59 Post subject: Re: Calcite Forms - (4) |
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An oddity
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Calcite with sand inclusions A French “super-classic”. Group of acute rhombohedral crystals of calcite that have grown including white sand. Bellecroix (Forêt), Fontainebleau, Seine-et-Marne, Ile-de-France, France Former Palix collection. Mined in the XIX Century Specimen size: 4.7 × 3.3 × 3 cm. Main crystal size: 1.7 × 1.5 cm. Photo from "Reference Specimens" |
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Tobi
Site Admin
Joined: 07 Apr 2009
Posts: 4112
Location: Germany
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Posted: Jun 09, 2010 09:47 Post subject: Re: Calcite Forms - (4) |
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When talking of oddities, here once again pictures of the calcite from Holzen quarry, North Rhine-Westphalia, Germany. See the last pages of my collection thread for further pictures and information about this specimen.
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The odd calcite twin. Size 25 mm. |
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Here a "normal" crystal from Holzen, grown on dolomite. Crystal size 15 mm. |
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am mizunaka
Joined: 09 Apr 2010
Posts: 2053
Location: USA
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Posted: Jun 15, 2010 02:58 Post subject: Re: Calcite Forms - (4) |
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Another calcite from the Roncari Quarry.
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A plate of doubly terminated calcites to 4 cm in length. Overall size 8.2 x 6.2 cm |
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Jordi Fabre
Overall coordinator of the Forum
Joined: 07 Aug 2006
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Location: Barcelona
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Posted: Jun 15, 2010 10:47 Post subject: Re: Calcite Forms - (4) |
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A beauty, isn't?
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Cobaltian Calcite Bou Azzer area, Tazenakht, Ouarzazate, Morocco. Mined in January 2006 Specimen size: 5.8 × 5 × 2.5 cm. Main crystal size: 0.8 × 0.7 cm. Fluorescence short UV & low fluorescence long UV Photo from "Reference Specimens" |
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The crystals shows well defined rhombohedron terminal faces |
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_________________ Audaces fortuna iuvat |
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Tobi
Site Admin
Joined: 07 Apr 2009
Posts: 4112
Location: Germany
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Posted: Jun 15, 2010 12:55 Post subject: Re: Calcite Forms - (4) |
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Jordi Fabre wrote: | A beauty, isn't? |
Jordi, it definitely IS! :-)
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Paul Bordovsky
Joined: 07 Nov 2008
Posts: 46
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Posted: Jun 20, 2010 12:31 Post subject: Re: Calcite Forms - (4) |
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I finally got around to shooting some new pics, and here are some calcites to add to this thread.
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Calcite discs on quartz ps. after calcite. Droujba mine, Bulgaria. 28cm. x 16cm. |
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Pagoda style calcite from Leiping mine, Chenzhou, China. The chinese dealer called it "mushroom" calcite. 16.3 x 9.5 cm. |
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Calcite from Terlingua, Texas, USA. From the Lone Star Mine. 32 x 21.5 cm. Although it does have a creamy white fluorescence, it does not have the famous blue fluorescence and phosphorescence under SW UV, like its more well known "Terlingua" brothers, which only came from one mine. |
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These crystals are clear with yellow phantoms. |
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Paul Bordovsky
Joined: 07 Nov 2008
Posts: 46
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Posted: Jun 20, 2010 12:47 Post subject: Re: Calcite Forms - (4) |
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I thought I'd add a few calcites local to the central Texas area, around Austin.. All are from Travis county, Texas, USA.
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"Gum drop" calcite, named by the collector. 19 x 21 cm. |
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"Dogtooth" calcite found near the previous gumdrop specimen. 10 x 8 cm. |
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Large calcite found during road construction of the Mopac expressway. The collector acid dipped this to clean it up. 14.5 cm. |
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Tracy
Joined: 15 Sep 2006
Posts: 551
Location: Toronto
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Posted: Jun 20, 2010 19:27 Post subject: Re: Calcite Forms - (4) |
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Finally I had a bit of free time and can contribute one of my own specimens! The lighting isn't ideal and doesn't show that the entire piece is white. I'm not sure exactly form these crystals have (there appear to be 5 sides to each crystal) but because the main crystals are very elongated they impart a "flower-like" the appearance to the specimen. From Daye Copper Mine, Daye Co., Huangshi Prefecture, Hubei Province, China. Size is about 13.5 x 7.5 x 4 cm.
- Tracy
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_________________ "Wisdom begins in wonder" - Socrates |
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: Jul 22, 2010 09:00 Post subject: Re: Calcite Forms - (4) |
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We have a question about cobalt calcite such as Jordi posted above https://www.mineral-forum.com/message-board/viewtopic.php?p=12126&highlight=#12126
We have a druzy which goes by "cobaltocalcite" (and other names). But under magnification the crystals appear orthorhombic. Is there such a thing as "cobalt aragonite" which would have this same color, or are the crystals so distorted sometimes in the cobalt calcite that they would appear not to fit calcite's forms?
My understanding is that in the cobalt calcite the cause of the color is bivalent Co in the octahedral site causing the amazing pink color in Jordi's specimen; I was contrasting that with bivalent cobalt in tetrahedral coordination in spinel causing the blue of "cobalt spinel" (as an example of the same chromophore causing radically different color in different ion coordinations and taking that further into a discussion of geometry affecting absorption of light). Then someone pointed out to me that the druzy doesn't look like calcite, but rather the polymorph aragonite...which blew my whole mini-project out of the water. I went back to study aragonite and whether it occurs in this color and if so, whether cobalt could would be in the same location - but, I don't find any mention of aragonite with cobalt. So asking collectors.
I am trying to get a photomicrograph, but with no luck so far of getting enough detail - perhaps others have some images of cobalt calcite druzy to which I could compare what I have in hand.
As a total distraction, attached is an aragonite with cyclic twinning making it appear hexagonal. I am holding out for a pink calcite that appears orthorhombic....
Elise
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_________________ Elise Skalwold |
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: Jul 22, 2010 13:07 Post subject: Re: Calcite Forms - (4) |
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uh oh, I am replying to my own post with belated insights from my collaborator - after looking at what I posted above, he wrote: "Well, I have spent the last hour or two looking at images of druzy (drusy) calcite and aragonite. The image you included on your inquiry looks nothing like ours. Everything about his druzy (Jordi's) says calcite, especially the rhombohedra. But here is a druzy-like pink aragonite: https://www.mindat.org/photo-142081.html . Don’t know if it is due to cobalt. Here is more pink druzy aragonite but not much like ours: https://www.mindat.org/photo-142150.html . I thought I saw blades, nothing as beautiful as this however: https://www.mindat.org/photo-186107.html . More like this: https://www.mindat.org/photo-35569.html . But then I went to drusy calcite and found images that look just like our specimen. One thing that makes me lean back toward ours being calcite is that the cleavage I observed in ours was what I would call perfect whereas , aragonite has imperfect cleavage. The only remaining problem with ours being calcite is the complete lack of rhombohedral crystal faces or rhombohedral cleavage – but that could simply be due to the way the crystals are all crowded into the site. Oh well, let me know what kind of feedback you get. I lean more toward it being calcite at this point."
Maybe now I can go back to my original project of cobalt calcite and cobalt spinel - but I would still enjoy seeing more examples of cobalt calcite and pink aragonite.
Cheers!
Elise
_________________ Elise Skalwold |
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kywawa
Joined: 17 Jul 2010
Posts: 6
Location: new york
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Posted: Jul 31, 2010 03:51 Post subject: Re: Calcite Forms - (4) |
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Oh,god..it's too beautiful and attractive.
_________________ Everything in the world is wonderful. Left your hearts, your soul, your power |
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am mizunaka
Joined: 09 Apr 2010
Posts: 2053
Location: USA
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Posted: Aug 08, 2010 05:06 Post subject: Re: Calcite Forms - (4) |
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Calcite within calcite crystals and the tiny tip of another poking out the top termination.
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Calcite from Bor Quarry Dalnegorsk Russia |
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nicu
Joined: 01 Sep 2010
Posts: 90
Location: Bucharest
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Posted: Sep 05, 2010 00:22 Post subject: Re: Calcite Forms - (4) |
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Hi,
I add here a few Calcites from my collection
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Black and White Calcite, Herja Mine, Maramures, Romania size specimen 15x8x8 cm collected in 1985 |
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Black and White Calcite Another photo |
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Calcite of Cavnic, Maramures, Romania, folk name 'Cavnicit' specimen size: 9x6x5 cm collected in 1986 spherical groups of brownish radials crystals, main crystal size 15 mm Fe-oxide inclusions |
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Black Calcite from Herja, Maramures, Romania specimen size: 17x11x16 cm |
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Yellow Calcite from Iara Mine, Cluj dep., Romania specimen size: 9x7x4 cm |
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: Mar 28, 2011 15:37 Post subject: Re: Calcite Forms - (4) |
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Pete Richards wrote: | Certainly Elise's specimen is consistent with the famous dolomite twins from Eugui. But examples of calcite twinned in this morphology are also known. It's worth checking out, but I think the similarity to Eugui dolomite is not conclusive. Simple tests would easily resolve the question, including the rate of fizz in dilute HCl compared to known calcite and dolomite examples. |
One year later, I finally was able to get into the case today to retrieve the suspect specimen labeled Calcite: https://www.mineral-forum.com/message-board/viewtopic.php?p=10730&highlight=#10730 A tiny drop of 10% nitric acid on a discreet part of the crystal had almost no visible fizzing (a drop on sample of calcite fizzed crazily). While it shows how much work is ahead of me checking labels all through the museum, it was also a lesson in not believing everything one reads, no matter the context (in this case a mineral museum). When writing or editing I use multiple references and cross-check everything in them, having found errors in textbooks, scientific papers, articles - not all with subsequent published erratum. But, just as Pete pointed out, my coworker said that it could not be a sight-ID as calcite can also look just like this. Now I am looking for the acquisition records to find out if there is any information about origin. In learning about minerals and mineral collecting over the past couple years, one revelation has been the amazing aspect of locality types and that collectors recognize them quickly, as Jordi and others recognized this dolomite. I went by morphology from a distance and a prejudiced love of calcite....along with the tag.
Cheers!
Elise
PS: I was also able to pull out a specimen labeled sphaerocolbaltite - discredited in Fleisher's 2008, but what if I had only looked in Bayliss.....lovely color though.
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javmex2
Joined: 06 Sep 2010
Posts: 120
Location: Chihuahua
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Posted: May 09, 2011 16:30 Post subject: Re: Calcite Forms - (4) |
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Some from Mexico.
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Hercules, Coahuila, Mexico Collected in 1992. |
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Naica, Chihuahua, Mexico Collected in past days this month |
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Mapimí, Durango, Mexico Size: 15 cms Collected in 2009. |
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am mizunaka
Joined: 09 Apr 2010
Posts: 2053
Location: USA
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Posted: Jul 19, 2011 22:14 Post subject: Re: Calcite Forms - (4) |
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A few more examples.
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Calcite with Sand Inclusions Bellecroix, Fontainebleau, Seine-et-Marne, Ile-de-France, France 6 x 3.6 cm |
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Calcite Interior, Jackson Co., South Dakota 10.2 x 5.8 cm |
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Calcite (Top View) Interior, Jackson Co., South Dakota 10.2 x 5.8 cm |
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am mizunaka
Joined: 09 Apr 2010
Posts: 2053
Location: USA
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Posted: Oct 25, 2012 23:26 Post subject: Re: Calcite Forms - (4) |
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Calcite on Siderite Herja Mine, Baia Mare, Maramure Co., Romania 7.5 x 4.5 cm. |
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mihailovici79
Joined: 07 Sep 2011
Posts: 111
Location: Timisoara
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Posted: Oct 26, 2012 12:45 Post subject: Re: Calcite Forms - (4) |
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Calcite from Romania:
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Calcite, Ocna de Fier, Romania |
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Calcite, Metaliferi Mountains, Romania |
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