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The information provided within this Forum about localities is only given to allow reference to them. Any visit to any of the localities requires you to obtain full permission and relevant information prior to your visit. FMF is strictly against any illicit activities related to collecting minerals.
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| Search found 51 matches |
| Author | Message |
|---|---|
 Topic: Nifontovite |
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| Linus Replies: 8 Views: 3940 |
 Forum: Minerals and Mineralogy Posted: Dec 09, 2023 15:52 Subject: Re: Nifontovite |
| Tired of looking at those skinny clear nifontovites? For the size freaks out there, here's one of the plumpest single nifontovites Ive seen (single crystal near center right edge on the photo), 0.5&qu ... | |
| Topic: Dissolution enables dolomite crystal growth near ambient conditions |
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| Linus Replies: 9 Views: 4439 |
Forum: Mineralogical Literature Posted: Nov 24, 2023 15:48 Subject: Re: Dissolution enables dolomite crystal growth near ambient conditions |
| I like to hear of your three methods of dolomite formation. I'm particularly a fan and supporter of the third method you describe, which I have seen in the field in several important mineral districts ... | |
| Topic: Calcite geode from Idar |
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| Linus Replies: 2 Views: 3047 |
Forum: Minerals and Mineralogy Posted: Apr 21, 2023 18:27 Subject: Re: Calcite geode from Idar |
| I think its cool! Wonder whether parts of it fluoresce? | |
| Topic: Amethyst |
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| Linus Replies: 17 Views: 8721 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 25, 2023 14:08 Subject: Re: Amethyst |
| Amir, I visited your quartz website, very nicely done! It really helps to clarify this situation. | |
| Topic: Amethyst |
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| Linus Replies: 17 Views: 8721 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 25, 2023 13:20 Subject: Re: Amethyst |
| I see Fluorite cubes. Could you test the hardness?
I agree it looks like fluorite, I see a lot of 90 degree angles and almost no conchoidal fractures. A hardness test would be very useful - does g ... |
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| Topic: Semi-spherical exterior, radiating interior stone |
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| Linus Replies: 31 Views: 12630 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 11, 2023 12:26 Subject: Re: Semi-spherical exterior, radiating interior stone |
| Hi, I do think your image of mcrowrock3 shows a centralized protrusion - thus shell is a better explanation for the spherical bottom. shell or coral, either way, I still am leaning towards fossil. The ... | |
| Topic: Semi-spherical exterior, radiating interior stone |
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| Linus Replies: 31 Views: 12630 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 10, 2023 20:16 Subject: Re: Semi-spherical exterior, radiating interior stone |
| Cretaceous age fossil corals are known from the San Antonio area of south Texas, and from north of Nuevo Laaredo, both approximately 200 kms from Zapata.I have enclosed a cross section drawing of a Cr ... | |
| Topic: Semi-spherical exterior, radiating interior stone |
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| Linus Replies: 31 Views: 12630 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 10, 2023 17:54 Subject: Re: Semi-spherical exterior, radiating interior stone |
| I guess the real question is, "was this transported? or found in outcrop"? judging from all the eocene sediments surrounding zapata, tx and the pronounced rounding and abrasion of the item I ... | |
| Topic: Semi-spherical exterior, radiating interior stone |
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| Linus Replies: 31 Views: 12630 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 10, 2023 17:15 Subject: Re: Semi-spherical exterior, radiating interior stone |
| oh come now, fossils can easily be preserved by silica (corals in the Horquilla Formation in Southern Arizona, petrified wood; and brachiopods on the Colorado Plateau; I have seen them preserved as we ... | |
| Topic: Semi-spherical exterior, radiating interior stone |
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| Linus Replies: 31 Views: 12630 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 10, 2023 14:25 Subject: Re: Semi-spherical exterior, radiating interior stone |
| I agree - fossil. Most all concretions form concentric rings, the radial pattern is not at all typical of a concretion. | |
| Topic: Brazil Amethyst |
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| Linus Replies: 1 Views: 9897 |
Forum: Mineralogical Literature Posted: May 31, 2022 18:41 Subject: Brazil Amethyst |
| Hi all! A couple months ago I ran across a brilliant old article by Rock Currier detailing one of his early trips to Rio Grande do Sul with lots of great photos. I can't find it now! Does anyone have ... | |
| Topic: Location in Romania |
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| Linus Replies: 5 Views: 4357 |
Forum: What is it? - Where is it from? Posted: Sep 30, 2021 17:31 Subject: Re: Location in Romania |
| just ran across this:
Boița is a commune in Sibiu County, Transylvania, Romania, at the foothills of the Cindrel Mountains, 22 km south of the county capital Sibiu |
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| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 24, 2021 14:52 Subject: Re: Black, metallic, yellow oxide? |
| Yes indeed. I'm trying to get some documentation on its possible whereabouts, but we'll have to see how that goes. | |
| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 23, 2021 17:36 Subject: Re: Black, metallic, yellow oxide? |
| I'm debating on the Connecticut provenance though, could also be Rwanda, Uganda... I'm hoping I may be able to tie that down too. You guys have been very helpful. I'm about 95% convinced on the specie ... | |
| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 23, 2021 17:34 Subject: Re: Black, metallic, yellow oxide? |
| with precious little info, I think you did great, than you! | |
| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 22, 2021 16:58 Subject: Re: Black, metallic, yellow oxide? |
| ... one of Rob's pieces... (oh and the yellow may be tungstite or similar...
"Ferberite Pseudomorph after Scheelite Ferberite Pseudomorph after Scheelite from Trumbull, Fairfield Co., Connect ... |
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| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 22, 2021 15:30 Subject: Re: Black, metallic, yellow oxide? |
| ferberrite ps scheelite??? | |
| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 22, 2021 15:20 Subject: Re: Black, metallic, yellow oxide? |
| well, we are closing in on it. XRF (Niton XL5) shows strong tungsten and iron... see the pic. | |
| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 21, 2021 20:37 Subject: Re: Black, metallic, yellow oxide? |
| Hi Bob, I think youre right about the orthorhombic, but the streak and pronounced cleavages suggest other than brookite... I think we're closing in on it! | |
| Topic: Black, metallic, yellow oxide? |
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| Linus Replies: 24 Views: 13594 |
Forum: What is it? - Where is it from? Posted: Jul 21, 2021 19:24 Subject: Re: Black, metallic, yellow oxide? |
| oh, and the whitish spots in the picture look to me slightly aplitic, they fluoresce a weak tan-yellow. | |
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