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
24 Feb-02:18:58 Re: taking great photographs (Marvinlewinsky)
24 Feb-02:10:53 Re: the joy of tucson, 2020 gail spann experience (Marvinlewinsky)
24 Feb-00:07:31 Re: the joy of tucson, 2020 gail spann experience (Gail)
24 Feb-00:02:32 Re: the joy of tucson, 2020 gail spann experience (Gail)
24 Feb-00:00:10 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:54:01 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:46:53 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:41:27 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:36:00 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:26:50 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:22:59 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:20:11 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-23:14:34 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-22:54:15 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-22:47:40 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-22:42:24 Re: the joy of tucson, 2020 gail spann experience (Gail)
23 Feb-17:14:59 Re: celestine (Bob Harman)
23 Feb-17:11:41 Re: collection of sante celiberti - a mineralogical trip through italy (Sante Celiberti)
23 Feb-14:13:03 Tucson show 2020 - the new discoveries! (2) (Jordi Fabre)
23 Feb-13:52:44 Tucson show 2020 - the new discoveries! (1) (Jordi Fabre)
23 Feb-13:01:53 Re: taking great photographs (Jesse Fisher)
23 Feb-12:27:14 Re: taking great photographs (Jordi Fabre)
23 Feb-12:14:45 Re: presentation of new members - from saskatoon, saskatchewan, canada (Don Lum)
23 Feb-10:53:06 Re: taking great photographs (Le Snelling)
23 Feb-09:08:19 Re: presentation of new members - from saskatoon, saskatchewan, canada (Firmo Espinar)

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
63309


The time now is Feb 24, 2020 02:41

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
Oddities from Brandberg, Namibia
  Goto page Previous  1, 2, 3, 4  Next
  Index -> Minerals and Mineralogy
Like
29


View previous topic :: View next topic  
Author Message

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Apr 20, 2014 14:15    Post subject: Re: Oddities from Brandberg, Namibia  

Jordi Fabre wrote:
Pierre Joubert wrote:
Hi Jordi. Is it possible to change the topic of this thread to' Oddities from Brandberg, Namibia'? This will allow me to show a few more different unusual minerals, most of which I do not know the identity of. By voorbaat dank!

Done!


Thank you very much Jordi! I will continue with a specimen consisting of Quartz, Calcite, Epidote and an unknown mineral, perhaps Chrysocolla. Whatever it is, it is something I have never seen from Brandberg area.



P1290780.JPG
 Description:
Quartz, calcite, epidote, and an unknown mineral.
Brandberg, Namibia
40 x 38 x 28 mm
The calcite has two types of crystalization.
 Viewed:  14228 Time(s)

P1290780.JPG



P1290785.JPG
 Description:
Quartz, calcite, epidote and an unknown mineral.
Brandberg, Namibia
40 x 38 x 28 mm
 Viewed:  14232 Time(s)

P1290785.JPG



P1290783.JPG
 Description:
Quartz, calcite, epidote, and an unknown mineral.
Brandberg, Namibia
40 x 38 x 28 mm
same as above.
 Viewed:  14230 Time(s)

P1290783.JPG



P1280843.JPG
 Description:
unknown mineral on quartz
Brandberg, Namibia
F.O.V. approximately 9 mm
 Viewed:  14243 Time(s)

P1280843.JPG



P1280845.JPG
 Description:
unknown mineral
Brandberg, Namibia
F.O.V approximately 9 mm
 Viewed:  14217 Time(s)

P1280845.JPG



P1280867.JPG
 Description:
unknown mineral
Brandberg, Namibia
F.O.V approximately 9 mm
 Viewed:  14208 Time(s)

P1280867.JPG



_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 02, 2014 10:13    Post subject: Re: Oddities from Brandberg, Namibia  

Here is a quartz crystal with a few gas bubbles captured in water, gas inclusions and some unusual crystal inclusions. My guess is that it is feldspar or dolomite. I do not know what the green mineral is. What do you think?

I do not agree with Brandberg being part of the Erongo region. It may be geographically correct but it is confusing as the two areas yield a different variety of mineral species and it is a distance from each other. Erongo itself has a number of subdivision areas like Spitzkoppe, Neu Scwaben, Karibib and off course, the Erongo mountains.



Clipboard02.jpg
 Mineral: Quartz with unknown inclusions.
 Dimensions: 53 x 26 x 20 mm
 Description:
 Viewed:  13869 Time(s)

Clipboard02.jpg



P1390623.jpg
 Mineral: Quartz with unknown inclusions.
 Locality:
Goboboseb Mountains, Brandberg area, Erongo Region, Namibia
 Dimensions: F.O.V. about 10 x 09 mm
 Description:
 Viewed:  13841 Time(s)

P1390623.jpg



P1390629.jpg
 Mineral: Quartz with unknown inclusions.
 Locality:
Goboboseb Mountains, Brandberg area, Erongo Region, Namibia
 Dimensions: F.O.V. about 10 x 09 mm
 Description:
 Viewed:  13883 Time(s)

P1390629.jpg



_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
1
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 03, 2014 02:43    Post subject: Re: Oddities from Brandberg, Namibia  

I found another crystal with the same inclusions; possibly from the same batch.


P1390805.JPG
 Mineral: Quartz with unknown inclusions.
 Locality:
Brandberg area, Erongo Region, Namibia
 Dimensions: F.O.V approximately11 x 08 mm
 Description:
 Viewed:  13806 Time(s)

P1390805.JPG



_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
1
   

ploum




Joined: 12 Nov 2007
Posts: 1183
Location: Near Annecy


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 03, 2014 03:22    Post subject: Re: Oddities from Brandberg, Namibia  

I think hematite for inclusion
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 03, 2014 03:50    Post subject: Re: Oddities from Brandberg, Namibia  

ploum wrote:
I think hematite for inclusion


Thank you. I am sorry, I should have been more specific. I am referring to the white cubic or triclinic(?) crystals. Best regards.

_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

Martin Rich




Joined: 15 Aug 2013
Posts: 127
Location: Lower Austria


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 03, 2014 16:23    Post subject: Re: Oddities from Brandberg, Namibia  

Hello Pierre!
The white crystals could be adularia with minor green coating of a chlorite mineral.

Martin

_________________
We are living on the matrix.
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 04, 2014 01:47    Post subject: Re: Oddities from Brandberg, Namibia  

Martin Rich wrote:
Hello Pierre!
The white crystals could be Adularia with minor green coating of a Chlorit mineral.

Martin


Thank you Martin. You are most likely right.

_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

marco campos-venuti




Joined: 09 Apr 2014
Posts: 192
Location: Sevilla


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 09, 2014 07:39    Post subject: Re: Oddities from Brandberg, Namibia  

The shape reminds me more of a carbonate, such as calcite, siderite, or dolomite.
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 09, 2014 07:58    Post subject: Re: Oddities from Brandberg, Namibia  

marco campos-venuti wrote:
The shape remembers more of a carbonate, as calcite, siderite, dolomite.


Hi Marco. Thank you for your interest. I found that dolomite and feldspar can be so similar when it comes to inclusions. Perhaps it is dolomite.

_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

Jordi Fabre
Overall coordinator of the Forum



Joined: 07 Aug 2006
Posts: 4413
Location: Barcelona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 09, 2014 08:25    Post subject: Re: Oddities from Brandberg, Namibia  

marco campos-venuti wrote:
The shape remembers more of a carbonate, as calcite, siderite, dolomite.

Probably not inside the Quartz due the formation temperature of the Quartz. A feldspar sounds more reasonable.
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 09, 2014 10:10    Post subject: Re: Oddities from Brandberg, Namibia  

Jordi Fabre wrote:
marco campos-venuti wrote:
The shape remembers more of a carbonate, as calcite, siderite, dolomite.

Probably not inside the Quartz due the formation temperature of the Quartz. A feldspar sounds more reasonable.


Hi Jordi. Now I will attempt to prove you wrong :-) Till then I am happy to settle with Martin Rich's initial observations. Regards.

_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

marco campos-venuti




Joined: 09 Apr 2014
Posts: 192
Location: Sevilla


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 10, 2014 06:33    Post subject: Re: Oddities from Brandberg, Namibia  

Dolomite in quartz is very common in Brazil. Here is an example.
Quartz can crystallize in a wide range of temperatures. But the crystal shape of feldspars from the Celsian-Hyalophane series is very similar to rhombohedral carbonates.



IMG_1188 (Medium).JPG
 Mineral: dolomite in quartz
 Locality:
Minas Gerais, Brazil
 Dimensions: 62 mm
 Description:
 Viewed:  13143 Time(s)

IMG_1188 (Medium).JPG


Back to top
Reply to topic Reply with quote
Like
1
   

Jordi Fabre
Overall coordinator of the Forum



Joined: 07 Aug 2006
Posts: 4413
Location: Barcelona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 10, 2014 11:37    Post subject: Re: Oddities from Brandberg, Namibia  

marco campos-venuti wrote:
Dolomite in quartz is very common in Brazil. Here an example.
Because quartz can crystallize in a wide range of temperatures.

True Marco, thank you to point out but I believe the deposits of Brandberg area are related with high-temperature geological processes.
Back to top
Reply to topic Reply with quote
Like
   

cascaillou




Joined: 27 Nov 2011
Posts: 228

View user's profile

Send private message

PostPosted: Dec 12, 2014 11:25    Post subject: Re: Oddities from Brandberg, Namibia  

Hi,
concerning the identity of those white crystals, you could try:
-LW and SW UV (if any fluorescence, report intensity and color of fluorescence, and also check in complete darkness if there's any residual phosphorescence once the UV have been cut)
-check the transparent ones for doubling of their inclusions/edges (with a good microscope)
-check for cleavages or any characteristic twinning under the microscope
-you could also try crossed polars under the microscope, checking for lamellar twining, if any.
-if one of the included crystals has decent transparency, you might even try conoscopy between crossed polars under the microscope (check for optical axis under crossed polars, and then use the conoscope)
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 12, 2014 12:06    Post subject: Re: Oddities from Brandberg, Namibia  

cascaillou wrote:
Hi,
concerning the identity of those white crystals, you could try:
-LW and SW UV (if any fluorescence, report intensity and color of fluorescence, and also check in complete darkness if there's any residual phosphorescence once the UV have been cut)
-check the transparent ones for doubling of their inclusions/edges (with a good microscope)
-check for cleavages or any characteristic twinning under the microscope
-you could also try crossed polars under the microscope, checking for lamellar twining, if any.
-if one of the included crystals has decent transparency, you might even try conoscopy between crossed polars under the microscope (check for optical axis under crossed polars, and then use the conoscope)


Hi Cascaillou. I have none of those items needed :-(

_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

cascaillou




Joined: 27 Nov 2011
Posts: 228

View user's profile

Send private message

PostPosted: Dec 12, 2014 12:14    Post subject: Re: Oddities from Brandberg, Namibia  

Christmas is coming! :-)
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 12, 2014 14:03    Post subject: Re: Oddities from Brandberg, Namibia  

cascaillou wrote:
Christmas is coming! :-)

Hi Cascaillou, shall I send you my postal address via PM? :-)

_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
   

Pierre Joubert




Joined: 09 Mar 2012
Posts: 1605
Location: Western Cape


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jan 14, 2015 11:35    Post subject: Re: Oddities from Brandberg, Namibia  

Hi Mike and Vic. I would like to continue our discussion on inverted crystals under this topic as the specimen comes from Tafelkop area, near Brandberg. Perhaps Peter, Duncan and other experts can chip in. As far as I know, 'inverted' crystals are hollow and formed slower than other gas inclusions. Sometimes these have water with an air bubble trapped inside.


P1420638.JPG
 Mineral: Quartz
 Locality:
Brandberg area, Erongo Region, Namibia
 Dimensions: 40 x 09 x 08 mm
 Description:
Quartz with inverted crystals.
 Viewed:  12127 Time(s)

P1420638.JPG



P1420654.JPG
 Mineral: Quartz
 Locality:
Brandberg area, Erongo Region, Namibia
 Dimensions: 40 x 09 x 08 mm
 Description:
Quartz with inverted crystals. Same as above.
 Viewed:  12107 Time(s)

P1420654.JPG



P1420662.JPG
 Mineral: Quartz
 Locality:
Brandberg area, Erongo Region, Namibia
 Dimensions: 40 x 09 x 08 mm
 Description:
Quartz with inverted crystals. Same as above.
 Viewed:  12106 Time(s)

P1420662.JPG



P1420669.JPG
 Mineral: Quartz
 Locality:
Brandberg area, Erongo Region, Namibia
 Dimensions: 40 x 09 x 08 mm
 Description:
Quartz with inverted crystals. Same as above.
 Viewed:  12151 Time(s)

P1420669.JPG



P1420680.JPG
 Mineral: Quartz
 Locality:
Brandberg area, Erongo Region, Namibia
 Dimensions: 40 x 09 x 08 mm
 Description:
Quartz with inverted crystals. Same as above
 Viewed:  12135 Time(s)

P1420680.JPG



_________________
Pierre Joubert


'The tree of silence bears the fruit of peace. '
Back to top
Reply to topic Reply with quote
Like
3
   

Michael Shaw
Site Admin



Joined: 30 Apr 2008
Posts: 1484
Location: Oklahoma


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jan 14, 2015 15:11    Post subject: Re: Oddities from Brandberg, Namibia  

Wonderful piece Pierre, and great photos.
Michael
Back to top
Reply to topic Reply with quote
Like
   

Don Lum




Joined: 03 Sep 2012
Posts: 2178
Location: Arkansas


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jan 14, 2015 17:53    Post subject: Re: Oddities from Brandberg, Namibia  

Pierre,

Great specimen and photographs.

Don

_________________
hogwild
Back to top
Reply to topic Reply with quote
Like
   
Display posts from previous:   
   Index -> Minerals and Mineralogy   All times are GMT - 5 Hours
Page 2 of 4
  Goto page Previous  1, 2, 3, 4  Next  

 
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 2006-2020


Powered by FMF