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
15 Dec-18:03:16 Re: don lum collection (Don Lum)
15 Dec-17:33:10 Re: a mineralogical trip through the states of usa - new jersey (Kushmeja)
15 Dec-17:20:03 Re: a mineralogical trip through the states of usa - new jersey (Frank Imbriacco)
15 Dec-16:38:52 Re: hasan abbasi's collection (H.Abbasi)
15 Dec-16:18:54 Re: hasan abbasi's collection (H.Abbasi)
15 Dec-15:42:56 Re: hasan abbasi's collection (H.Abbasi)
15 Dec-11:28:30 Re: faden quartz crystals - (26) (Marco Campos-venuti)
15 Dec-08:59:10 Re: collection of dontgogreen (Dontgogreen)
15 Dec-06:43:45 Re: faden quartz crystals - (26) (Roger Warin)
14 Dec-22:46:18 Re: minerals of dr congo, katanga. (Roger Warin)
14 Dec-16:40:57 The mizunaka collection - quartz (Am Mizunaka)
14 Dec-15:54:05 Re: franjungle collection (Franjungle)
14 Dec-14:18:24 Re: collection of michael shaw (Crosstimber)
14 Dec-14:11:30 Re: prospecting pegmatite for schorl: need help. (Cascaillou)
14 Dec-12:18:14 Re: faden quartz crystals - (26) (Frei Hans)
14 Dec-12:17:10 Re: prospecting pegmatite for schorl: need help. (Philippe Durand)
14 Dec-10:38:53 Re: percentage of minerals known (Riccardo Modanesi)
14 Dec-04:13:50 Re: percentage of minerals known (Alfredo)
14 Dec-03:53:10 Re: percentage of minerals known (Riccardo Modanesi)
13 Dec-22:09:25 Re: percentage of minerals known (Alfredo)
13 Dec-17:59:43 Re: prospecting pegmatite for schorl: need help. (Cascaillou)
13 Dec-16:01:15 Re: prospecting pegmatite for schorl: need help. (Josele)
13 Dec-15:58:23 Re: minerals of dr congo, katanga. (Roger Warin)
13 Dec-13:53:58 Re: minerals of dr congo, katanga. (Roger Warin)
13 Dec-13:27:15 Re: prospecting pegmatite for schorl: need help. (Peter Lemkin)

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
36709


The time now is Dec 16, 2017 04:20

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
Cornish Chalcocite but from where?
  
  Index -> What is it? - Where is it from?
Like
1


View previous topic :: View next topic  
Author Message

jfc035




Joined: 14 Jul 2015
Posts: 10
Location: Rennes

View user's profile

Send private message

PostPosted: May 28, 2017 06:20    Post subject: Cornish Chalcocite but from where?  

Hello
I've found this week-end in a local show this small chalcocite in an old collection (2.5 cm large). The only information was "Chalcocite - UK"
The crystals are highly lustrous and razor-shaped. They sit on a piece of what I assume to be iron-stained amorphous quartz ; there is a bit of limonitic oxidation on the backside of chalcocite.
Does it ring any bell to Brit colleagues / collectors where it may actually come from?
Thanks
Jean-François



100_1890.JPG
 Description:
 Viewed:  1562 Time(s)

100_1890.JPG



100_1898.JPG
 Description:
 Viewed:  1561 Time(s)

100_1898.JPG



100_1892.JPG
 Description:
 Viewed:  1562 Time(s)

100_1892.JPG


Back to top
Reply to topic Reply with quote
Like
   

jfc035




Joined: 14 Jul 2015
Posts: 10
Location: Rennes

View user's profile

Send private message

PostPosted: May 28, 2017 06:23    Post subject: Re: Cornish Chalcocite but from where?  

I forgot to mention that it seems there is a bit a chalcopyrite underneath the chalcocite (see top two pictures)
Back to top
Reply to topic Reply with quote
Like
   

Tobi




Joined: 07 Apr 2009
Posts: 2539
Location: Good Old Germany


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: May 28, 2017 07:25    Post subject: Re: Cornish Chalcocite but from where?  

I'm neither an expert for chalcocite nor for British minerals, but I know such superb and lustrous crystals of that mineral from Geevor Mine in Cornwall ...
Back to top
Reply to topic Reply with quote
Like
1
   

GneissWare




Joined: 07 Mar 2008
Posts: 1264
Location: California


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: May 28, 2017 14:20    Post subject: Re: Cornish Chalcocite but from where?  

There are many Cornwall localities, and likely other UK localities. If you don't get an answer here, there is a very active facebook group, search for "Collectors of British Minerals". Ian Bruce is on that page, and may know.

Great specimen by the way!
Back to top
Reply to topic Reply with quote
Like
   

markbeckett




Joined: 06 Oct 2016
Posts: 41
Location: Cornwall


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: May 29, 2017 06:01    Post subject: Re: Cornish Chalcocite but from where?  

Hi jfc035 - I agree with Tobi - if this is a UK specimen, it is almost certainly from Geevor Mine, near St Just, Cornwall. Other localities in Cornwall, such as St Ives Consols and Cook's Kitchen at Pool also hosted chalcocite, but I have never seen really lustrous 'razor-like' crystals like yours from anywhere else in UK - other than from Geevor. North Pig Lode and Hanging Wall Vein at Geevor were well-known for producing these excellent crystals - many of these specimens were collected, even in the later years of the old mine (mining in this district has been going on for over 300 years). The quartz matrix with a spot of chalcopyrite is also quite probable (for Geevor).

Thanks for showing this great little piece :-)
Back to top
Reply to topic Reply with quote
Like
   

jfc035




Joined: 14 Jul 2015
Posts: 10
Location: Rennes

View user's profile

Send private message

PostPosted: May 29, 2017 14:19    Post subject: Re: Cornish Chalcocite but from where?  

Dear All
thanks for your replies and tips.
Best regards
Jean-François
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 2006-2017


Powered by FMF