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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: Mar 03, 2010 05:35 Post subject: Re: Collection of Miguel. |
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Miguel: I would suggest that it does not have lepidocrocite inclusions. There are no verified reports of lepidocrocite ever having been found in quartz. All examples of such red inclusions that have been tested, that I have been able to track down, are hematite. No one knows where the idea of lepidocrocite occurring as an inclusion in quartz started, but I have been doing everything humanly possible to discourage the referring of hematite inclusions as lepidocrocite. My latest effort will appear soon in Rocks & Minerals.
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John S. White
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 03, 2010 07:54 Post subject: Re: Collection of Miguel. |
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Hello John. Thank you for your advice. The person who said me it is Lepidocrocite was the seller in Namibia. I attach a pic of an other crystal from Goboboseb with this kind of inclusions.
Te main crystal is 1 cm wide.
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| Quartz from Goboboseb. Detail. |
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24223 Time(s) |
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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: Mar 03, 2010 08:08 Post subject: Re: Collection of Miguel. |
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It is a wonderful piece Miguel and I am sure you can assume that the inclusions are hematite.
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John S. White
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 03, 2010 08:38 Post subject: Re: Collection of Miguel. |
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| Yes, of course John. It is Hematites. Thank you!
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 04, 2010 08:46 Post subject: Re: Collection of Miguel. |
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Amethyst from Goboboseb, Namibia. 2006.
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| Amethyst. 7,3 x 2,3 x 2 cm. |
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24168 Time(s) |
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| Amethyst. 7,3 x 2,3 x 2 cm. Detail. |
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24134 Time(s) |
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Debbie Woolf
Joined: 09 Feb 2009
Posts: 168
Location: Kent
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| Posted: Mar 04, 2010 11:14 Post subject: Re: Collection of Miguel. |
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Gorgeous Amethyst !
Many Namibian & S. African 'local' dealers say its Lepidocrocite inclusion but as John has stated it is in fact Hematite.
Lovely crystals keep sharing them with us.
Debbie
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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| Posted: Mar 04, 2010 14:07 Post subject: Re: Collection of Miguel. |
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| John S. White wrote: | | ..... No one knows where the idea of lepidocrocite occurring as an inclusion in quartz started, but I have been doing everything humanly possible to discourage the referring of hematite inclusions as lepidocrocite. My latest effort will appear soon in Rocks & Minerals. |
Your note on this is good timing for me as I write up a description of the quartz below -- I look forward to your expanding on the topic in your upcoming article. In relation to when it started, I had noted that in his first PhotoAtlas Vol 1, John Koivula identified them as lepidocrocite, as did Gübelin in his Internal World of Gemstones (in fact EG called them "foils of ruby mica."). Many years later, in John's second volume of the PhotoAtlas series, he corrected that to say that it started with a misidentification in the 1960s; maybe he could tell you when/where that was exactly. In the Hyrsl and Niederayer quartz inclusion book, it has a short note under lepidocrosite simply stating that it is a misidentifcation of hematite - this was in context of refuting something written by Rykart in 1995 identifying inclusions in quartz as lepidocrocite. When I showed my mineralogist co-worker the inclusions below, he said "neat hematite!" which was good enough for me. We liked the symmetry. It will be nice to include your article in reference to debunking the myth!
Cheers,
Elise
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| Hematite in Quartz, transmitted light. |
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24063 Time(s) |
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Elise Skalwold |
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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: Mar 05, 2010 05:36 Post subject: Re: Collection of Miguel. |
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The misidentification of hematite as lepidocrocite goes way back in time, long before Koivula or Rykart mistakenly referred to it as such. No one appears to know when it first appeared in the literature, at least I have never been able to establish that. I am, however, a bit surprised that both authors chose to call these inclusions lepidocrocite without questioning it.
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Andreas Gerstenberg
Joined: 04 Mar 2010
Posts: 336
Location: Chemnitz
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| Posted: Mar 05, 2010 05:49 Post subject: Re: Collection of Miguel. |
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José,
the gypsum is a so-called "montmartre twin". Maybe it is a piece from its type locality Montmartre, Paris, France (however, I would say so...).
Andreas
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 05, 2010 05:58 Post subject: Re: Collection of Miguel. |
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| Andreas, I remember that I bought this piece in Paris. So, I think you are right. Thank you!
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Elise
Joined: 22 Dec 2009
Posts: 243
Location: New York State
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| Posted: Mar 05, 2010 10:09 Post subject: Re: Collection of Miguel. |
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| John S. White wrote: | | The misidentification of hematite as lepidocrocite goes way back in time, long before Koivula or Rykart mistakenly referred to it as such. No one appears to know when it first appeared in the literature, at least I have never been able to establish that. I am, however, a bit surprised that both authors chose to call these inclusions lepidocrocite without questioning it. |
I should explain that I was prompted to jump into the thread both because of the hematite correction and the wonderful picture which José posted above of the colorless quartz with the inclusions arranged at an angle- but I failed to include the connection when I wrote the previous posting.
I had been researching the specimen I posted above which reminded me of the arrangement of inclusions in José's crystal, though this view is looking parallel to the c axis and Jose's inclusions are oriented differently. I had found a description of the same in Gems & Gemology Sp84 "Pseudo Star Quartz" (ed C. Fryer, author K. Hurwit) which helped me understand what is happening, but seeing the crystal in its natural state above gives a more complete understanding even if different. In that entry they had noted "some, not all, of the needles displayed a morphological change from acicular goethite to flat plate-like form known as lepidocrocite." (the needles are oriented on the horizontal crystal axes and meet at the junctions of the major and minor rhombohedral faces of the quartz -- in this case, the cut of the cab made it take on a star or a trapiche-like effect).
Knowing John's books by heart, I was aware of the correction and had it noted next to my specimen description (I probably am the only person in upstate NY who has three sets of the books and wouldn't mind a 4th just so I don't have to reach too far). But, in all of my references, I had not run across an explanation of why there was a change of opinion on the identification (only notes that it was previously erroneous). I didn't go further back than the G&G 84 or Dr. Gübelin's book as I was just trying to confirm what is dictating the inclusion pattern seen here.
I sure appreciate the input and information from FMF members so I don't make mistakes in my write-ups! As a gemologist coming in the back door of mineralogy and writing for a geology department, I need all the help I can get before I get put through the realworld tests! Checking and cross-checking literature throughout the years is a lesson in itself! Thanks, John!
Elise
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 09, 2010 06:10 Post subject: Re: Collection of Miguel. |
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Hello Debbie. I am happy that you like my crystals.
The next crystal is an other quartz from the Goboboseb, Namibia. 2002.
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| Amethyst and Smoky Quartz.10x3,2x3 cm. |
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23950 Time(s) |
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| Amethyst and Smoky Quartz. Detail. 10x3,2x3 cm. |
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23918 Time(s) |
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 10, 2010 06:53 Post subject: Re: Collection of Miguel. |
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Quartz from Goboboseb. Namibia. 2002.
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23863 Time(s) |
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 15, 2010 09:54 Post subject: Re: Collection of Miguel. |
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Amethyst and Smoky Quartz from Goboboseb, Namibia.
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| Amethyst and Smoky Quartz. 8,8x2,2x1,3 |
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23841 Time(s) |
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| Amethyst and Smoky Quartz. 8,8x2,2x1,3 cm. Detail. |
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23823 Time(s) |
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 16, 2010 10:25 Post subject: Re: Collection of Miguel. |
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Smoky and Amethyst Quartz. Goboboseb. Namibia. 2000.
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| Smoky and Amethyst Quartz. 13,5x6x3,5 cm. |
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23704 Time(s) |
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| Description: |
| Smoky and Amethyst Quartz. 13,5x6x3,5 cm. Detail |
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23690 Time(s) |
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Debbie Woolf
Joined: 09 Feb 2009
Posts: 168
Location: Kent
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| Posted: Mar 16, 2010 10:42 Post subject: Re: Collection of Miguel. |
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| Jose, I adore crystals from this region. I noticed you have two dates 2000 & 2002 on the crystals, was you visiting this area then ? I was there in 2001.
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 17, 2010 04:05 Post subject: Re: Collection of Miguel. |
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| Hello Debbie. I didn´t visit Namibia in 2000 or 2002. The crystals came to me from there directly, but I have never been to Namibia. I like very much also this kind of crystals, because of its amethyst color, its inner world, its beauty, even its very good smoky color.
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 19, 2010 09:21 Post subject: Re: Collection of Miguel. |
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Quartz from Goboboseb. Namibia. 2002.
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23560 Time(s) |
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| Quartz. 8,8x4,5 cm. Detail |
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23554 Time(s) |
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 20, 2010 05:56 Post subject: Re: Collection of Miguel. |
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Amethyst and Smoky Quartz. Goboboseb. Namibia. 2005.
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| Amethyst and Smoky Quartz. 11x3,2x2,5 cm. |
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23483 Time(s) |
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| Amethyst and Smoky Quartz. 11x3,2x2,5 cm. Detail-2. |
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| Description: |
| Amethyst and Smoky Quartz. 11x3,2x2,5 cm. Detail. |
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23451 Time(s) |
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| Amethyst and Smoky Quartz. 11x3,2x2,5 cm. Water bubble. |
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23456 Time(s) |
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| Amethyst and Smoky Quartz. 11x3,2x2,5 cm. Detail-4. |
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José Miguel
Joined: 09 Apr 2007
Posts: 157
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| Posted: Mar 21, 2010 20:59 Post subject: Re: Collection of Miguel. |
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Amethyst from Goboboseb. Namibia.
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| Amethyst. 11,5 x 5,2 x 3,8 cm |
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23462 Time(s) |
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| Description: |
| Amethyst. 11,5 x 5,2 x 3,8 cm |
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23446 Time(s) |
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| Amethyst. 11,5 x 5,2 x 3,8 cm. |
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23431 Time(s) |
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