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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 671 matches |
| Author | Message |
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 Topic: Article on Naica and Gypsum |
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| Peter Megaw Replies: 4 Views: 416 |
 Forum: Mineralogical Literature Posted: Oct 14, 2021 09:54 Subject: Re: Article on Naica and Gypsum |
| https://www.foro-minerales.com/forum/gen_imag/Cristales_Naica-Chemical_Society_Reviews/Cristales_Naica-Chemical_Society_Reviews.pdf
Here is a much more detailed treatment of the science... Still ... |
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| Topic: Tracing the dealer "Minerals Engineering" or Brian Petrovic |
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| Peter Megaw Replies: 2 Views: 596 |
Forum: The histories behind mineral specimens Posted: Sep 17, 2021 09:30 Subject: Re: Tracing the dealer "Minerals Engineering" or Brian Petrovic |
| Tom, You might try Andy Stucki at Siber and Siber in Zurich | |
| Topic: Ajoite From Messina |
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| Peter Megaw Replies: 3 Views: 570 |
Forum: Minerals and Mineralogy Posted: Aug 27, 2021 16:56 Subject: Re: Ajoite From Messina |
| Roger, Ajoite is famous for "deteriorating" into chrysocolla, so my first guess would be that that's what you're seeing rather than a compositional shift within an ajoite-XXX series. (yes, I ... | |
| Topic: Fluorite from where? |
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| Peter Megaw Replies: 10 Views: 1223 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Aug 18, 2021 14:14 Subject: Re: Fluorite from where? |
| Might also help if you gave it a bath! | |
| Topic: Fluorite from where? |
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| Peter Megaw Replies: 10 Views: 1223 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Aug 18, 2021 13:54 Subject: Re: Fluorite from where? |
| Could you include a photograph of the bottom...sometimes even a bit of matrix helps identify or eliminate possibilities | |
| Topic: Tsumeb Zincolivenite association - light blue acicular mineral = ? |
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| Peter Megaw Replies: 3 Views: 677 |
Forum: Minerals and Mineralogy Posted: Aug 04, 2021 10:08 Subject: Re: Tsumeb Zincolivenite Association - light blue acicular mineral = ? |
| with the pale blue color and extremely elongate crystals I would suspect aurichalcite over rosasite...but there are several acicular blue alternatives for Tsumeb...stranskyite? | |
| Topic: 2021 Denver Show(s) |
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| Peter Megaw Replies: 3 Views: 1354 |
Forum: Mineral Shows Posted: Jul 17, 2021 10:01 Subject: Re: 2021 Denver Show(s) |
| Worth noting that the Denver Council Show...the outfit that kicked things off in Denver...is celebrating FLUORITE as their theme this year...should be very popular. Most (all?) Of the talks will be on ... | |
| Topic: What is this rock formation? |
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| Peter Megaw Replies: 5 Views: 1037 |
Forum: What is it? - Where is it from? Posted: Jul 04, 2021 20:35 Subject: Re: What is this rock formation? |
| What formation is it from? Edwards?
This looks like a textbook concretion...a banded onion-like body that forrms during diagenesis/lithification where something (fossil, organic nucleus etc) acts a ... |
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| Topic: Unknown mineral from Pikes Peak pegmatite |
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| Peter Megaw Replies: 23 Views: 3340 |
Forum: What is it? - Where is it from? Posted: Jun 13, 2021 16:41 Subject: Re: Unknown mineral from Pikes Peak pegmatite |
| Good point on the monoclinic Pete...and euclase is monoclinic
But Euclase means "true/easy cleavage" and according to Bob it has no obvious cleavage (although it is unclear if he means basa ... |
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| Topic: Unknown mineral from Pikes Peak pegmatite |
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| Peter Megaw Replies: 23 Views: 3340 |
Forum: What is it? - Where is it from? Posted: Jun 13, 2021 15:50 Subject: Re: Unknown mineral from Pikes Peak pegmatite |
| Danburite maybe? | |
| Topic: Strange green & brown geode |
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| Peter Megaw Replies: 8 Views: 1639 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Jun 06, 2021 15:02 Subject: Re: Strange Green & Brown Geode |
| There is very similar material from Concepcion del Oro in Mexico and probably at least one Arizona locality. You might try browsing the pictures of malachite + quartz on mindat for Concepcion, Bisbee ... | |
| Topic: Opal soil finds |
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| Peter Megaw Replies: 3 Views: 1064 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Apr 19, 2021 09:43 Subject: Re: Opal soil finds |
| Given that these are coming from an opal deposit , the hardness and KISS says something siliceous is a likely possibility. The fibrous texture looks like satin spar (gypsum) or certain pedogenic carbo ... | |
| Topic: Green, purple, white and orthoclase conglomerate? |
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| Peter Megaw Replies: 3 Views: 901 |
Forum: FOR BEGINNERS: What is it? Where is it from? Posted: Apr 19, 2021 09:22 Subject: Re: Green, purple, white and orthoclase conglomerate? |
| Charly, looks more like a piece of pegmatite with a granite xenolith and late epidote veining to me. Not quite sure I see purple exactly...looks like it might be fine-grained dispersed specularite. T ... | |
| Topic: Fluorite Santa Eulalia |
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| Peter Megaw Replies: 3 Views: 1247 |
Forum: What is it? - Where is it from? Posted: Apr 10, 2021 17:57 Subject: Re: Fluorite Santa Eulalia |
| Linus...Mina El Carmen is the westernmost mine in the West Camp! | |
| Topic: anyone know this "Thulite-Hornblende" locality? |
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| Peter Megaw Replies: 5 Views: 1292 |
Forum: What is it? - Where is it from? Posted: Apr 05, 2021 09:41 Subject: Re: anyone know this "Thulite-Hornblende" locality? |
| Thanks Folks!
Good to reconnect it with a locality, the pink is really very pretty Another 50 cent "score" at the sale was this fake fossil from Morocco!! |
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| Topic: anyone know this "Thulite-Hornblende" locality? |
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| Peter Megaw Replies: 5 Views: 1292 |
Forum: What is it? - Where is it from? Posted: Apr 04, 2021 16:39 Subject: anyone know this "Thulite-Hornblende" locality? |
| Picked up this polished slab labeled "Thulite Hornblende" at a estate sale because the pink is quite pretty (much better than my phone camera rendition) and the reaction rims around it. It ... | |
| Topic: Creedite - Is Pink Different than Purple, Navidad Mine (Mina Navidad) |
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| Peter Megaw Replies: 9 Views: 2801 |
Forum: Minerals and Mineralogy Posted: Mar 10, 2021 19:01 Subject: Re: Creedite - Is Pink Different than Purple, Navidad Mine (Mina Navidad) |
| Given that Creedite is highly light sensitive and will lose color relatively rapidly in sunlight, I doubt that Mn is the chromophore and suspect that a more elusive color source is operating here. | |
| Topic: Locality for Mexican Quartz specimens |
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| Peter Megaw Replies: 4 Views: 1564 |
Forum: What is it? - Where is it from? Posted: Mar 04, 2021 13:00 Subject: Re: Locality for Mexican Quartz specimens |
| There are some quartzes with that kind of "waist" from the San Antonio Mine at Santa Eulalia, but they are from the primary zone and are not associated with oxides of iron or copper. Also si ... | |
| Topic: Locality for Mexican Quartz specimens |
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| Peter Megaw Replies: 4 Views: 1564 |
Forum: What is it? - Where is it from? Posted: Mar 03, 2021 20:51 Subject: Re: Locality for Mexican Quartz specimens |
| Brent, the first one is almost certainly Concepcion del Oro, Zacatecas...the second one probably (95%) is,...the shape of the crystals is pretty distinctive | |
| Topic: Heat changes some minerals - how? |
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| Peter Megaw Replies: 11 Views: 2691 |
Forum: Off-Topic and Introductions Posted: Jan 29, 2021 11:28 Subject: Re: Heat changes some minerals - how? |
| Tom...depends a lot on the mineral...in some cases changes in structure may be reversible when it cools off...although in some minerals the changes might be metastable and the reversion might take a l ... | |
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