We use cookies to show content based on your preferences. If you continue to browse you accept their use and installation. More information. >


FMF - Friends of Minerals Forum, discussion and message board
The place to share your mineralogical experiences


Spanish message board






Newest topics and users posts
16 Jul-17:31:41 The mizunaka collection - chalcoalumite (Am Mizunaka)
16 Jul-12:44:28 Architectural spinel from vietnam / #mvm (minerals - virtual museum) collection (Jordi Fabre)
16 Jul-12:18:23 New book: minerals of britain and ireland 2009-2024 - a review (Jordi Fabre)
16 Jul-09:38:43 Re: collection of michael shaw (Michael Shaw)
15 Jul-13:05:10 Sphalerite with calcite from Áliva, spain / #mvm (minerals - virtual museum) collection (Jordi Fabre)
15 Jul-11:32:34 Goesdorf mine (luxembourg) antimony (Roger Warin)
14 Jul-18:03:59 Malachite after azurite on goethite (Silvia)
14 Jul-16:43:05 The mizunaka collection - quartz (Am Mizunaka)
14 Jul-09:34:45 Re: collection of michael shaw (Michael Shaw)
13 Jul-12:19:45 Lazurite (lapis lazuli) from afghanistan / #mvm (minerals - virtual museum) collection (Jordi Fabre)
12 Jul-23:04:14 Re: collection of volkmar stingl (Volkmar Stingl)
12 Jul-09:00:56 Re: the mim museum in beirut, lebanon (Mim Museum)
12 Jul-06:59:21 Re: collection from dany mabillard (Dany Mabillard)
12 Jul-00:49:24 Re: are there pyrite balls found in verzino? (Herwig)
12 Jul-00:25:14 Re: are there pyrite balls found in verzino? (Roger Warin)
12 Jul-00:08:38 Re: are there pyrite balls found in verzino? (Roger Warin)
11 Jul-17:36:07 The mizunaka collection - fluorite (Am Mizunaka)
11 Jul-14:14:25 Re: slice schalenblende (Mathias)
11 Jul-14:08:21 Re: czech rockhounding adventures – agates & amethysts (Stoner)
11 Jul-08:12:55 Czech rockhounding adventures – agates & amethysts (Stoner)
11 Jul-08:03:52 Re: are there pyrite balls found in verzino? (James Catmur)
11 Jul-02:33:28 Re: collection of michael shaw (Michael Shaw)
11 Jul-00:24:28 Re: collection of volkmar stingl (Volkmar Stingl)
10 Jul-13:46:07 Re: are there pyrite balls found in verzino? (Dany Mabillard)
10 Jul-13:45:53 Veszelyite from sanguozhuang, china / #mvm (minerals - virtual museum) collection (Jordi Fabre)

For lists of newest topics and postings click here


RSS RSS

View unanswered posts

Why and how to register

Index Index
 FAQFAQ RegisterRegister  Log inLog in
 {Forgotten your password?}Forgotten your password?  

Like
122711


The time now is Jul 16, 2025 18:35

Search for a textSearch for a text   

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.
Uknown mineral specimen
  
  Index -> What is it? - Where is it from?
Like
1


View previous topic :: View next topic  
Author Message

Mathias




Joined: 01 Apr 2018
Posts: 153
Location: Vlodrop

View user's profile

Send private message

PostPosted: Dec 01, 2019 07:56    Post subject: Uknown mineral specimen  

Dear FMF friends,

Today I purchased a specimen that came with the following label: "Psilomelane, Brazil".
The vendor said that he actually doesn't know what it is, he got the specimen as one of a large, mainly undocumented, collection. I believe that it isn't psilomelane.

The specimen is approximately 10 cm, I thought it might be Quartz after Aragonite. But looking on internet, I can't find any similar specimen.

Is there anybody who recognizes this mineral?

Thanks,

Mathias



755A.JPG
 Dimensions: 10 cm * 8 cm * 5 cm
 Description:
 Viewed:  6737 Time(s)

755A.JPG



755B.JPG
 Description:
 Viewed:  6726 Time(s)

755B.JPG



755C.JPG
 Description:
 Viewed:  6733 Time(s)

755C.JPG


Back to top
Reply to topic Reply with quote
Like
   

Mathias




Joined: 01 Apr 2018
Posts: 153
Location: Vlodrop

View user's profile

Send private message

PostPosted: Dec 01, 2019 09:23    Post subject: Re: Uknown mineral specimen  

There's some additional information:

When I point a laserlight on the reddish portions of the specimen, the area lightens up by dispersion of the laser beam. So these portions are opaque.

You wouldn't expect such properties in case of psilomelane or otherwise iron oxides.

Best regards,

Mathias.
Back to top
Reply to topic Reply with quote
Like
   

Kevin Conroy




Joined: 03 Dec 2018
Posts: 78
Location: Saint Louis, Missouri

View user's profile

Send private message

PostPosted: Dec 01, 2019 09:35    Post subject: Re: Uknown mineral specimen  

Hi, I think that this is probably chalcedony after aragonite from Valle de las Plumas, Argentina.
Back to top
Reply to topic Reply with quote
Like
   

alfredo
Site Admin



Joined: 30 Jan 2008
Posts: 1013


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 01, 2019 10:29    Post subject: Re: Uknown mineral specimen  

I agree with Kevin about the ID and the locality.
Nice pseudomorph!
Back to top
Reply to topic Reply with quote
Like
1
   

Roger Warin




Joined: 23 Jan 2013
Posts: 1243


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 01, 2019 15:10    Post subject: Re: Uknown mineral specimen  

Yes, I think so.
Here is a chacedony covered with limonite psm after barite.



85-Perimorph-Kipushi_R.jpg
 Mineral: limonite after Baryte
 Locality:
Kipushi, Katanga Copper Crescent, Katanga (Shaba), Democratic Republic of the Congo (Zaire)
 Description:
 Viewed:  6639 Time(s)

85-Perimorph-Kipushi_R.jpg


Back to top
Reply to topic Reply with quote
Like
   
Display posts from previous:   
   Index -> What is it? - Where is it from?   All times are GMT - 5 Hours
Page 1 of 1
    

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


All pictures, text, design © Forum FMF 2006-2025


Powered by FMF