|
A general guide for using the Forum with some rules and tips
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.
|
| Search found 19 matches |
| Author | Message |
|---|---|
 Topic: Fluorite crystallography? |
|
| Johan Kjellman Replies: 28 Views: 124414 |
 Forum: Minerals and Mineralogy Posted: Oct 01, 2024 05:15 Subject: Re: Fluorite crystallography? |
| I came back to this thread, having forgotten and identified the first image first as a cube-octahedron, but then, after counting the exposed faces of the most obvious crystal (I could see 8) I came to ... | |
| Topic: Fluorite crystallography? |
|
| Johan Kjellman Replies: 28 Views: 124414 |
Forum: Minerals and Mineralogy Posted: Dec 13, 2023 02:57 Subject: Re: Fluorite crystallography? |
| I agree again - and withdraw my claim.
And Pete, you point directly at what I now think so many of us, although experienced, keep on misinterpreting these combos. We are all fast and confident in ide ... |
|
| Topic: Fluorite crystallography? |
|
| Johan Kjellman Replies: 28 Views: 124414 |
Forum: Minerals and Mineralogy Posted: Dec 12, 2023 17:58 Subject: Re: Fluorite crystallography? |
| Another Naica fluorite, which according to Pete's analysis would be cube-dodechahedral habit. From the find circa 2005.
I 100 % agree with Pete's analysis of how to differentiate between the two co ... |
|
| Topic: Crystallography question |
|
| Johan Kjellman Replies: 6 Views: 8206 |
Forum: Minerals and Mineralogy Posted: Jun 17, 2022 03:30 Subject: Re: Crystallography question |
| Check,
Richards 1996 Canadian Mineralogist 34, pp. 615-621. It's on twinned hambergite from Stak Nala and should help you a bit. cheers |
|
| Topic: Elbaite, ending moor's head |
|
| Johan Kjellman Replies: 9 Views: 11150 |
Forum: Minerals and Mineralogy Posted: Jun 11, 2022 18:31 Subject: Re: Elbaite, ending moor's head |
| Roger,
I think we can agree that the Moor's head signifies an abrupt change in fluid chemistry. A proposed explanation for that abrupt change has been that the pegmatite/pegmatite pocket cracks open ... |
|
| Topic: Elbaite, ending moor's head |
|
| Johan Kjellman Replies: 9 Views: 11150 |
Forum: Minerals and Mineralogy Posted: Jun 11, 2022 10:40 Subject: Re: Elbaite, ending moor's head |
| Roger,
I hate this, especially those sites where one registered say 5 years ago in order to see or get something, and then come back say 5 years later and try to register (cause one's completely for ... |
|
| Topic: Elbaite, ending moor's head |
|
| Johan Kjellman Replies: 9 Views: 11150 |
Forum: Minerals and Mineralogy Posted: Jun 10, 2022 15:34 Subject: Re: Elbaite, ending moor's head |
| Federico Pezzotta has at least touched upon similar questions.
Two titles of his: Color anomalies at the termination of pegmatitic gem-tourmaline crystals from Elba Island (Tyrrhenian Sea, Italy): a ... |
|
| Topic: More Label Translation |
|
| Johan Kjellman Replies: 9 Views: 9028 |
Forum: What is it? - Where is it from? Posted: Jun 10, 2022 05:51 Subject: Re: More Label Translation |
| No worries, I mean no harm, either way the information's out.
cheers |
|
| Topic: More Label Translation |
|
| Johan Kjellman Replies: 9 Views: 9028 |
Forum: What is it? - Where is it from? Posted: Jun 10, 2022 04:12 Subject: Re: More Label Translation |
| ... it looks like a discussion of the crystal habit, but otherwise I am lost. Thanks in advance!
Jesse, I have attached an answer for you because this "smart" system kicks me out all th ... |
|
| Topic: Photos of epitaxy - (16) |
|
| Johan Kjellman Replies: 55 Views: 185577 |
Forum: Featured Columns of FMF Posted: Oct 20, 2021 14:47 Subject: Columbite on Samarskite |
| Sample 1998-8184 from Museum für Naturkunde in Berlin, type sample from Gustav Rose. | |
| Topic: Black, metallic, yellow oxide? |
|
| Johan Kjellman Replies: 24 Views: 21065 |
Forum: What is it? - Where is it from? Posted: Jul 24, 2021 12:18 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: Bob Cook wins the 2021 John S. White Mineral Legacy Award |
|
| Johan Kjellman Replies: 2 Views: 19983 |
Forum: The histories behind mineral specimens Posted: May 01, 2021 12:58 Subject: Re: Bob Cook wins the 2021 John S. White Mineral Legacy Award |
| Bobcookite not cookeite!
cheers ____________________________________________ Fixed. Thanks Johan! |
|
| Topic: Aragonite "drill bit" twin |
|
| Johan Kjellman Replies: 16 Views: 26418 |
Forum: Minerals and Mineralogy Posted: Mar 31, 2020 06:29 Subject: Re: aragonite "drill bit" twin |
| Also, note that Haüy always publish individual images of the separate contributing crystals for the twin formations - each one in its actual orientation. In this case, figures 236-239.
cheers |
|
| Topic: Aragonite "drill bit" twin |
|
| Johan Kjellman Replies: 16 Views: 26418 |
Forum: Minerals and Mineralogy Posted: Mar 31, 2020 06:26 Subject: Re: aragonite "drill bit" twin |
| Thanks, Johan and Jordi. What I'm seeing in the figure appears to have 2-fold symmetry (2 crystals intergrown). My specimen definitely has 3-fold symmetry around the twin axis. The forms present ap ... | |
| Topic: Aragonite "drill bit" twin |
|
| Johan Kjellman Replies: 16 Views: 26418 |
Forum: Minerals and Mineralogy Posted: Mar 30, 2020 15:46 Subject: Re: aragonite "drill bit" twin |
| Thanks. Can you possibly scan that figure? Or is it available on-line (I did a search but was unable to find it).
Bob, I just pm'd you the link as it couldn't be posted here. PM me your email if ... |
|
All times are GMT - 5 Hours |
FAQ 
Register
Log in
Forgotten your password?
