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Antonio Alcaide
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Joined: 23 Aug 2009
Posts: 314
Location: Spain
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Antonio Alcaide
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Joined: 23 Aug 2009
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Location: Spain
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am mizunaka
Joined: 09 Apr 2010
Posts: 2040
Location: USA
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Posted: Sep 02, 2011 19:43 Post subject: Re: Mineral specimens with inclusions |
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Quartz with rutile inclusions.
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Quartz Dalbandin, Balochistan, Pakistan 7.5 x 5 cm. |
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37361 Time(s) |
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vic rzonca
Joined: 18 Nov 2008
Posts: 820
Location: MA
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Posted: Sep 02, 2011 19:45 Post subject: Re: Mineral specimens with inclusions |
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On re-reading my entry, it seems a little pedestrian to ask, is an inclusion confined to the inbound side of the of the included matrix? And do inclusions manifest themselves on the surface, where they might become a specimen on matrix? I just dropped in, pardon me.
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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Posted: Sep 02, 2011 20:37 Post subject: Re: Mineral specimens with inclusions |
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vic rzonca wrote: | On re-reading my entry, it seems a little pedestrian to ask, is an inclusion confined to the inbound side of the of the included matrix? And do inclusions manifest themselves on the surface, where they might become a specimen on matrix? I just dropped in, pardon me. |
This is one of my own favorite pieces - the included crystals break the surface and some form nice "specimens on matrix"- only appreciated under the microscope. The quartz crystal cluster below has blue tourmaline throughout, along with other inclusions I haven't identified. I am basing the tourmaline ID on that the crystals are strongly pleochroic (very dark blue and pale blue perpendicular to the long axis), striations along their length and the distinctive tourmaline cross-section seen as they break the surface of the quartz. They give the quartz a beautiful blue color, though in the top photo, while trying to get the sprays at the base of the quartz to show, they are blown-out. The blue is seen better in the crystal fragment in the next photo, oriented so two prism faces show. A tourmaline crystal is shown on the microscope monitor popping up through a cluster of unknown crystals embedded in the quartz face -- there are others coming through elsewhere sans yellowish crystals, but they don't show the form as nicely as this little one.
There is an interesting recently released paper on blue quartz for those who would like to know more about blue quartz colored by inclusions: Distinctive properties of rock-forming blue quartz: inferences from a multi-analytical study of submicron mineral inclusions.W. Seifert, D. Rhede, R. Thomas, H.-J. Förster, F. Lucassen, P. Dulski and R. Wirth. Mineralogical Magazine,2011, Volume 75, Number 3
Cheers!
Elise
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Blue Quartz (quartz included with blue tourmaline) unknown 35mm wide x 40 mm high |
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Quartz (included with blue tourmaline), crystal fragment showing prism face junction unknown 30mm wide x 25mm high |
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tourmaline on quartz and unknown xtls (detail of crystal fragment in above photo). unknown approx. 1.0 mm |
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_________________ Elise Skalwold |
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Duncan Miller
Joined: 25 Apr 2009
Posts: 138
Location: South Africa
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Posted: Sep 03, 2011 02:00 Post subject: Re: Mineral specimens with inclusions |
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Elise
You are scholarly, gracious, good humoured, and you write extremely well. I think there is great merit in your introducing some gemmology to this forum, Jordi's prejudice against crystal choppers notwithstanding! After all, the internal world of gemstones is also the internal world of minerals, and a crystal doesn't have to have faces to be crystalline.
I have arranged for the cutter of one of the Orange river quartz cabochons with haematite spots to bring it to our gem and mineral club meeting today, where I will photograph it and send you the photo privately, as we are now agreed the spots are artefacts, and so off topic.
Duncan
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Duncan Miller
Joined: 25 Apr 2009
Posts: 138
Location: South Africa
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Posted: Sep 03, 2011 02:15 Post subject: Re: Mineral specimens with inclusions |
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This is an edited re-post of a specimen in Peter Megaw's 'sand crystal' thread.
This smoky quartz with aegerine is from Malosa, Malawi. The aegerine crystals penetrate and poke out of all sides of the quartz crystal. Most of them are terminated, some of them doubly where they penetrate right through the quartz crystal. So, how did this grow? Did the aegerine nucleate before the quartz, which then partially engulfed it?
Duncan
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Aegerine and quartz Malosa, Malawi 70 mm long |
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John S. White
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Joined: 04 Sep 2006
Posts: 1295
Location: Stewartstown, Pennsylvania, USA
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Posted: Sep 03, 2011 05:29 Post subject: Re: Mineral specimens with inclusions |
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Another one, this one a bit different. This is a chlorite-included quartz from the Tipling mine, Dhading district, Nepal, in which inclusion-free quartz grew over the termination creating a scepter. The piece is 8.5 cm tall.
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_________________ John S. White
aka Rondinaire |
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John S. White
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Joined: 04 Sep 2006
Posts: 1295
Location: Stewartstown, Pennsylvania, USA
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Posted: Sep 03, 2011 05:37 Post subject: Re: Mineral specimens with inclusions |
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The inclusions in quartz from Pakistan described as rutile by am mizunaka look to me very much like astrophyllite, which appears to be relatively common in quartzes from Zagi Mountain in the Northwest Frontier Province.
_________________ John S. White
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al mar
Joined: 17 Feb 2009
Posts: 19
Location: Biscay, Spain
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Posted: Sep 03, 2011 05:45 Post subject: Re: Mineral specimens with inclusions |
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Elise, I have seen some very similar blue quartz specimens from Brazil .
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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: Sep 03, 2011 05:48 Post subject: Re: Mineral specimens with inclusions |
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Here's one for Vic to scratch his head over. This is goethite in amethystine quartz from Rio Grando do Sul, Brazil. It would appear that the goethite grew first on the surface of a larger goethite-included quartz crystal, then it became engulfed by quartz. One assumes that the growth of the two minerals was almost simultaneous.
A John Koivula photo.
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_________________ John S. White
aka Rondinaire |
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silvio steinhaus
Joined: 15 Jan 2011
Posts: 51
Location: São Paulo
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Posted: Sep 04, 2011 20:40 Post subject: Re: Mineral specimens with inclusions |
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Amethyst with various inclusions, calcite, cristobalite, goethite, and the red stuff in the picture, I do not know what it is.
The area of the photo is 14 x 12mm piece is 160 x 175mm, with many inclusions undetermined.
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Amethyst with various inclusions, calcite, cristobalite, goethite, and the red stuff in the picture, I do not know what it is. Ametista do Sul, Rio Grande do Sul, Brazil The area of the photo is 14 x 12mm piece is 160 x 175mm, with many inclusions undetermined. |
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vic rzonca
Joined: 18 Nov 2008
Posts: 820
Location: MA
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Posted: Sep 04, 2011 21:25 Post subject: Re: Mineral specimens with inclusions |
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It's really amazing how, on a molecular level these, these bits find themselves and arrange themselves in such a wonderful way that makes us ponder them. Simo-nucleotidic scilicic euhedral growth over goethite. I may be wrong. Just kidding, I know nothing. I still wonder what make's an inclusion. Where are it's boundaries. I would suppose it would be totally surrounded by it's binding mineral, no penetrations. Could someone clarify.
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am mizunaka
Joined: 09 Apr 2010
Posts: 2040
Location: USA
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Posted: Sep 05, 2011 04:20 Post subject: Re: Mineral specimens with inclusions |
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Quartz with fluorite inclusions.
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Quartz with Fluorite Amborompotsy, Ambatofinandrahana District, Fianarantsoa Province, Madagascar 13 x 6.4 cm |
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37062 Time(s) |
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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: Sep 05, 2011 04:50 Post subject: Re: Mineral specimens with inclusions |
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The fluorite in quartz specimen just shown by Am provides an excellent opportunity to respond to Vic's question. These Madagascar specimens are really interesting because some of the fluorites are entirely embedded or inclosed in quartz and some are partially exposed at the surface. Those that are/were partially exposed are gone! The cavities are octahedral-shaped, but empty. It is very difficult to imagine how these could have been dissolved and removed via just a tiny opening where they were not covered by quartz. The piece in Am's photos beautifully illustrates this feature.
So, Vic, in my opinion inclusions do not have to be completely enclosed in a host mineral, they often extend beyond the surface. This is particularly true for extremely elongated fibrous or needlelike minerals such as aegirine from Malawi. I doubt that there is a definition in the popular literature that would exclude crystals that extend beyond the surface from being considered inclusions.
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Antonio Alcaide
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Joined: 23 Aug 2009
Posts: 314
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Posted: Sep 05, 2011 10:39 Post subject: Re: Mineral specimens with inclusions |
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John S. White wrote: |
So, Vic, in my opinion inclusions do not have to be completely enclosed in a host mineral, they often extend beyond the surface. This is particularly true for extremely elongated fibrous or needlelike minerals such as aegirine from Malawi. I doubt that there is a definition in the popular literature that would exclude crystals that extend beyond the surface from being considered inclusions.
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Another example with part of one species inside and part outside the host mineral: quartz with possibly elbaite inclusions from Spain. The second example is an hydrocarbons included quartz interesting because of the centered position of the bitumen inclusions.
Regards
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Quartz with Elbaite inclusions Badajoz, Spain 6 x 3,5 cm Elbaite not analyzed. It looks like schorl but has green gleams at its edges and points. Most Elbaites protrude the quartz, but they can be easily seen inside it, so the greyish color. |
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Quartz with Elbaite Badajoz, Spain Close-up of the previous specimen |
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Quartz with bitumen inclusions Jinkouhe District, Leshan Prefecture, Sichuan Province, China 7,5 x 4,5 cm Although this is not the best example, other specimens from the same locality displays perfect centered inclusions at the junctions of the quartz crystals. |
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Quartz with bitumen inclusions Jinkouhe District, Leshan Prefecture, Sichuan Province, China 7,5 x 4,5 cm. Close-up of the previous specimen |
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_________________ Life is the shortest crystal |
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Jean louis lebret
Joined: 26 Jun 2011
Posts: 16
Location: Elbeuf
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Posted: Sep 05, 2011 14:33 Post subject: Re: Mineral specimens with inclusions |
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A gaz bubble in a liquid inclusion (fluorite from Naica, Mexico)
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Jordi Fabre
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Joined: 07 Aug 2006
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Location: Barcelona
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Posted: Sep 06, 2011 06:38 Post subject: Re: Mineral specimens with inclusions |
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xenolithos wrote: | Elise
You are scholarly, gracious, good humoured, and you write extremely well.! |
Absolutely!!!
xenolithos wrote: |
I think there is great merit in your introducing some gemmology to this forum, Jordi's prejudice against crystal choppers notwithstanding!
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I have nothing against great threads like this one, but against the junk basar of catchpenny "jewelry" that tends to flood many minerals shows as invasive species! ;-)
Here you have my humble aportation to this great thread. Please FMFers, add more!!
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Apophyllite-(KF) with Julgoldite-Fe inclusions Jalgaon, Maharashtra India. Mined about 1988 Specimen size: 9.8 × 7 × 4.7 cm. Former Jan Buma Zeolite Collection Photo: Reference Specimens |
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Smoky Quartz with unkown (maybe Albite) inclusion and Chlorite Probably from Diamantina, Minas Gerais, Brazil. Mined on November 2007 Specimen size: 11 × 10.5 × 5.1 cm. Photo: Reference Specimens |
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John S. White
Site Admin
Joined: 04 Sep 2006
Posts: 1295
Location: Stewartstown, Pennsylvania, USA
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Posted: Sep 06, 2011 07:55 Post subject: Re: Mineral specimens with inclusions |
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Here is a nice inclusion in a fluorite cleavage from Cave-in-Rock, Illinois. The cleavage is about 3 cm across. The inclusion is the tiny dot just to the right of the center of the cleavage. When magnified you can see a gas bubble in liquid and under the microscope it is possible to see that the bubble is flattened against all of the six sides of the rectangular hole in the fluorite.
The magnified photo was taken by Russell Feather, gemologist in the Mineral Sciences Dept. of the Smithsonian Institution.
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_________________ John S. White
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vic rzonca
Joined: 18 Nov 2008
Posts: 820
Location: MA
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Posted: Sep 06, 2011 08:15 Post subject: Re: Mineral specimens with inclusions |
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That is amazing John! Great shot!
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