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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 150 matches |
| Author | Message |
|---|---|
 Topic: Quartz Japan Twin |
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| marco campos-venuti Replies: 9 Views: 2520 |
 Forum: Minerals and Mineralogy Posted: Aug 17, 2025 16:46 Subject: Re: Quartz Japan Twin |
| Thank Bob. I used the prism striations and I get 76.
Can you share your article? I found online only the preview of the first page. |
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| Topic: Quartz Japan Twin |
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| marco campos-venuti Replies: 9 Views: 2520 |
Forum: Minerals and Mineralogy Posted: Aug 17, 2025 11:59 Subject: Re: Quartz Japan Twin |
| Lateral view | |
| Topic: Quartz Japan Twin |
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| marco campos-venuti Replies: 9 Views: 2520 |
Forum: Minerals and Mineralogy Posted: Aug 17, 2025 11:45 Subject: Re: Quartz Japan Twin |
| Back side | |
| Topic: Quartz Japan Twin |
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| marco campos-venuti Replies: 9 Views: 2520 |
Forum: Minerals and Mineralogy Posted: Aug 17, 2025 11:42 Subject: Re: Quartz Japan Twin |
| Thanks to both Bobs. I actually rushed it too quickly, and it's obviously not a Japan twin. I measured an angle close to 78 degrees, so I assume it could be a Grieserntal twin (76.26). I'm happy with ... | |
| Topic: Quartz Japan Twin |
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| marco campos-venuti Replies: 9 Views: 2520 |
Forum: Minerals and Mineralogy Posted: Aug 16, 2025 13:40 Subject: Quartz Japan Twin |
| The photo shows a 13.6 cm Japan twin quartz from Minas Gerais, Brazil.
Japan twin quartz crystals are considered typical contact twins. By definition, in a contact twin, the two individuals meet on a ... |
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| Topic: Peridot on Lapis ??? |
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| marco campos-venuti Replies: 18 Views: 39695 |
Forum: What is it? - Where is it from? Posted: Aug 16, 2025 04:30 Subject: Re: Peridot on Lapis ??? |
| It is diopside with lazurite from Kokcha Valley. | |
| Topic: Libyan Desert Glass Structure |
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| marco campos-venuti Replies: 71 Views: 100935 |
Forum: Minerals and Mineralogy Posted: Jul 02, 2025 10:06 Subject: Re: Libyan Desert Glass Structure |
| I see epigenetic inclusions in LDG_14, not leaves. | |
| Topic: Libyan Desert Glass Structure |
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| marco campos-venuti Replies: 71 Views: 100935 |
Forum: Minerals and Mineralogy Posted: Jul 02, 2025 09:12 Subject: Re: Libyan Desert Glass Structure |
| An impression is a fossil.
Absolutely not. And first of all you have to demonstrate the impression of what it is. I do not see any biological structure in your "impressions". |
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| Topic: Libyan Desert Glass Structure |
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| marco campos-venuti Replies: 71 Views: 100935 |
Forum: Minerals and Mineralogy Posted: Jul 02, 2025 08:49 Subject: Re: Libyan Desert Glass Structure |
| The presence of carbon and some organic molecules does not mean that they are fossils. No primary biological structure has been found. | |
| Topic: Libyan Desert Glass Structure |
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| marco campos-venuti Replies: 71 Views: 100935 |
Forum: Minerals and Mineralogy Posted: Jun 30, 2025 14:39 Subject: Re: Libyan Desert Glass Structure |
| Still the ignition temperature of a seed is in the order of 2-300 C and melting point of glass is around 800 C. | |
| Topic: Libyan Desert Glass Structure |
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| marco campos-venuti Replies: 71 Views: 100935 |
Forum: Minerals and Mineralogy Posted: Jun 30, 2025 12:24 Subject: Re: Libyan Desert Glass Structure |
| Dear Craig, I admire the perseverance and illusion you put into your study.
However, you cannot hunt for fossils inside a glass that was formed at temperatures estimated to be above 2750°C. If the ro ... |
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| Topic: Gwindel Skutterudite? |
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| marco campos-venuti Replies: 3 Views: 1739 |
Forum: Minerals and Mineralogy Posted: Jun 30, 2025 12:07 Subject: Re: Gwindel Skutterudite? |
| Dear Roger and Pete, thank you for your comments. The title of the post was intentionally provocative. However, I would like to open the controversy.
Mindat clearly says that "any gwindel is nec ... |
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| Topic: Gwindel Skutterudite? |
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| marco campos-venuti Replies: 3 Views: 1739 |
Forum: Minerals and Mineralogy Posted: Jun 28, 2025 14:11 Subject: Gwindel Skutterudite? |
| A curiosity I found in Sainte Marie this year. This skutterudite crystal from Bou Azzer is twisted. It was a typical Moroccan lot consisting of a box with at least 30 crystals and all of them showed t ... | |
| Topic: Ghost dendrite |
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| marco campos-venuti Replies: 7 Views: 3779 |
Forum: Minerals and Mineralogy Posted: May 03, 2025 04:17 Subject: Re: Ghost dendrite |
| I show you the back of the cabochon made of white opal. The dendrite is all inside. This is the drawer where it has been for 13 years. The only change was the addition of the azurite and malachite sam ... | |
| Topic: Ghost dendrite |
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| marco campos-venuti Replies: 7 Views: 3779 |
Forum: Minerals and Mineralogy Posted: May 02, 2025 02:20 Subject: Ghost dendrite |
| Years ago I cut a beautiful clear opal cabochon with a beautiful well-centered black dendrite. The best quality of that cabochon was that it was from Cabo de Gata, Almeria, Spain a little-known locati ... | |
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