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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 620 matches |
| Author | Message |
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 Topic: Gwindel Skutterudite? |
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| Pete Richards Replies: 3 Views: 854 |
 Forum: Minerals and Mineralogy Posted: Jun 29, 2025 13:59 Subject: Re: Gwindel Skutterudite? |
| This is a very interesting, obviously twisted crystal. I have never seen one like it. Perhaps you should have purchased all 30 of them!
My own opinion (since Roger asked) is that this should not ... |
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| Topic: Skutterudite |
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| Pete Richards Replies: 4 Views: 1159 |
Forum: Micros & Macros - Images of Minerals Posted: Jun 04, 2025 20:01 Subject: Re: Skutterudite |
| Where is the skutterudite? What is the purple mineral? This looks rather different from typical material from Cobalt, Ontario. What do the Canadians among us think? | |
| Topic: Locality for Albite from the Dauphiné |
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| Pete Richards Replies: 3 Views: 1398 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: May 26, 2025 15:13 Subject: Re: Locality for albite from Dauphine |
| I don't know about the locality, but I have some doubts whether these are really pericline twins. They look more like normal (but nicely formed) albite twins to me. | |
| Topic: Quartz Twins |
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| Pete Richards Replies: 6 Views: 3007 |
Forum: Minerals and Mineralogy Posted: May 07, 2025 08:22 Subject: Re: Quartz Twins |
| Thanks for posting some very interesting crystals!
Bob Morgan made some good comments, with which I agree. I will add some additional thoughts, hopefully helpful. I want to try to make a genera ... |
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| Topic: Ghost dendrite |
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| Pete Richards Replies: 7 Views: 2547 |
Forum: Minerals and Mineralogy Posted: May 02, 2025 18:34 Subject: Re: Ghost dendrite |
| This is an amazing change!
Does any part of the dendrite intersect the surface of the cabochon, including the "stem"? |
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| Topic: A true morphological twin of quartz according to the Dauphiné law. |
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| Pete Richards Replies: 5 Views: 3580 |
Forum: What is it? - Where is it from? Posted: Mar 03, 2025 18:01 Subject: Re: A true morphological twin of quartz according to the Dauphiné law. |
| Frondel, in Dana's System of Mineralogy 7th edition vol. 3 pag3 81 figures 4 and 5 illustrates Dauphiné contact twins. In these, there are two crystals in contact along their lengths, with their c-a ... | |
| Topic: A true morphological twin of quartz according to the Dauphiné law. |
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| Pete Richards Replies: 5 Views: 3580 |
Forum: What is it? - Where is it from? Posted: Mar 02, 2025 20:20 Subject: Re: A true morphological twin of quartz according to the Dauphiné law. |
| An interesting post, Roger, and two very nice specimens. Yes, Dauphiné twins. Probably.
As it happens, Carl Francis and I have just published an article in Rocks & Minerals on Brazil-law twin ... |
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| Topic: Calcite crystal habit |
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| Pete Richards Replies: 3 Views: 2447 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 23, 2025 16:09 Subject: Re: Calcite crystal habit |
| These crystals are rhombohedra. | |
| Topic: I’ve exhausted all local help! Please help me identify this? |
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| Pete Richards Replies: 4 Views: 3033 |
Forum: What is it? - Where is it from? Posted: Feb 06, 2025 13:32 Subject: Re: I’ve exhausted all local help! Please help me identify this? |
| If it's non-magnetic, it is not an iron meteorite.
Consider the possibility that it is a partially-refined metal - a smelting product - rather than a natural rock or mineral. |
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| Topic: Unknown banded mineral from shores of lake Buttermere, Cumbria. UK |
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| Pete Richards Replies: 5 Views: 2812 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Feb 06, 2025 13:28 Subject: Re: Unknown banded mineral from shores of lake Buttermere, Cumbria. UK |
| My guess is that it is quartz, based on the appearance of the columns in close-up. It could also be barite or gypsum, which are known to form similar stretch textures. | |
| Topic: Helvine with Quartz or Garnet? |
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| Pete Richards Replies: 17 Views: 5885 |
Forum: What is it? - Where is it from? Posted: Jan 27, 2025 16:18 Subject: Re: Helvine with Quartz or Garnet? |
| A magnet will tell you if magnetite is present, but I don't see anything that looks like magnetite. As helvine or genthelvite it is much more valuable than garnet! | |
| Topic: Axinite locality in France? |
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| Pete Richards Replies: 3 Views: 2245 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Jan 07, 2025 17:17 Subject: Re: Axinite locality in France? |
| Here is a suggestive citation from the Axinite page of Mindat:
Gautron, Laurent, Meisser, Nicolas (2001) Prehnite from La Combe De La Selle, Saint Christophe-en-Oisans, Isère, France. The Mineralog ... |
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| Topic: Can't read / decode this label to identify the fluorite location... |
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| Pete Richards Replies: 12 Views: 6651 |
Forum: What is it? - Where is it from? Posted: Nov 26, 2024 11:06 Subject: Re: Can't read / decode this label to identify the fluorite location... |
| Germany (or Austria) certainly seems to make the most sense. As for Switzerland, a Mindat search for "Grube" (mine or pit) with no further locality specification brings up only two matches i ... | |
| Topic: Pezzottaite, new specimens |
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| Pete Richards Replies: 1 Views: 4127 |
Forum: Minerals and Mineralogy Posted: Oct 19, 2024 17:44 Subject: Re: Pezzottaite, new specimens |
| It appears that the orange color was deposited by growth on the (0001) end faces of the crystal, and perhaps was not deposited at all in the earliest period of growth. The question then becomes, what ... | |
| Topic: what is this? A purple tourmaline grown out from the base of a skeletal quartz? |
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| Pete Richards Replies: 8 Views: 4619 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Aug 28, 2024 14:11 Subject: Re: what is this? A purple tourmaline grown out from the base of a skeletal quartz? |
| I am sorry, but I think it is very unlikely that the purple prism is amethyst. Perhaps there is a thin film of quartz on the purple mineral that gave a deceptive reading. | |
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