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

FMF English Forum is moderated by John S. White and Peter Megaw
 

Spanish message board






Newest topics and users posts
09 Dec-04:52:01 Re: new generation for picture - ploum (Ploum)
08 Dec-15:19:35 Re: don lum collection (Don Lum)
08 Dec-12:59:13 Re: fun with mineralogy (Firmo Espinar)
08 Dec-06:58:43 Re: new generation for picture - ploum (Ploum)
07 Dec-17:36:22 Re: new generation for picture - ploum (Ploum)
07 Dec-13:10:12 Re: asbestos name change (Peter Lemkin)
07 Dec-10:55:28 Re: collection of michael shaw (Michael Shaw)
07 Dec-03:46:08 Re: new generation for picture - ploum (Ploum)
07 Dec-02:50:51 The mizunaka collection - quartz (Am Mizunaka)
06 Dec-16:11:47 Fun with mineralogy (Cascaillou)
06 Dec-05:11:52 Re: collection of firmo espinar (Firmo Espinar)
05 Dec-05:37:49 Re: new generation for picture - ploum (Ploum)
04 Dec-20:28:22 Re: asbestos name change (Woody Thompson)
04 Dec-18:09:03 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
04 Dec-16:10:55 Re: new generation for picture - ploum (Ploum)
04 Dec-14:27:18 Re: "jaguar" agates from wy (Bob Harman)
04 Dec-13:31:57 Re: "jaguar" agates from wy (Jrh4)
04 Dec-11:39:46 Re: a mineralogical trip through the regions of the uk - england / county durham (Jesse Fisher)
04 Dec-11:00:27 Re: munich show (mineralientage) 2019 (John S. White)
04 Dec-09:22:45 Re: munich show (mineralientage) 2019 (Tony L. Potucek)
04 Dec-04:56:00 Re: asbestos town name change (James Catmur)
04 Dec-03:20:27 Re: a mineralogical trip through germany / sachsen - saxony (Tobi)
04 Dec-03:19:33 Re: "jaguar" agates from wy (Jordi Fabre)
03 Dec-19:52:58 Re:"jaguar" agates from wy (Jrh4)
03 Dec-19:39:11 Re: a mineralogical trip through germany / sachsen - saxony (Jesse Fisher)

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
60673


The time now is Dec 09, 2019 05:40

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
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: 108
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:  224 Time(s)

755A.JPG



755B.JPG
 Description:
 Viewed:  222 Time(s)

755B.JPG



755C.JPG
 Description:
 Viewed:  223 Time(s)

755C.JPG


Back to top
Reply to topic Reply with quote
Like
   

Mathias




Joined: 01 Apr 2018
Posts: 108
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: 65
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: 762


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: 936


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), Congo DR (Zaire)
 Description:
 Viewed:  114 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 2006-2019


Powered by FMF