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
17 Aug-16:23:52 Re: collection of michael shaw (Michael Shaw)
17 Aug-10:30:35 Re: east coast mineral and fossil show 2019 (Vic Rzonca)
17 Aug-09:39:03 Need help to confirm the composition of a specimen (Dany Mabillard)
17 Aug-09:15:51 Re: collection from dany mabillard (Dany Mabillard)
17 Aug-08:41:31 Re: collection of firmo espinar (Firmo Espinar)
17 Aug-08:28:46 Re: collection of michael shaw (Dany Mabillard)
16 Aug-14:07:29 Re: collection of michael shaw (Michael Shaw)
16 Aug-13:37:41 Re: east coast mineral and fossil show 2019 (Vic Rzonca)
15 Aug-20:27:10 Re: collection of ras (Robert Seitz)
15 Aug-16:18:24 The mizunaka collection - calcite (Am Mizunaka)
15 Aug-15:43:34 Re: collection of fiebre verde - muzo (#744) (Fiebre Verde)
15 Aug-14:55:15 Re: new generation for picture - ploum (Ploum)
14 Aug-11:05:00 Re: collection of michael shaw (Michael Shaw)
13 Aug-22:38:19 Re: could this be opal? (Steveb)
13 Aug-15:18:31 Re: could this be opal? (Andreas)
13 Aug-15:10:40 Re: could this be opal? (Kushmeja)
13 Aug-15:06:42 Could this be opal? (Andreas)
13 Aug-14:29:08 The mizunaka collection - quartz with calcite (Am Mizunaka)
13 Aug-11:17:13 Re: collection of philippe durand (Philippe Durand)
13 Aug-09:48:26 Re: don lum collection (Don Lum)
13 Aug-02:50:46 Re: don lum collection (Tobi)
12 Aug-20:38:33 Re: don lum collection (Don Lum)
12 Aug-15:42:21 Re: east coast mineral and fossil show 2019 (Bob Harman)
12 Aug-15:33:46 Re: does anyone know what the proper name for "jack rock" is? (Bob Harman)
12 Aug-13:05:06 Re: does anyone know what the proper name for "jack rock" is? (Dale Hallmark)

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
57498


The time now is Aug 17, 2019 19:37

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
What could the locality of this grey fluorite cluster (with small cubic crystals) be?
  
  Index -> What is it? - Where is it from?
Like
9


View previous topic :: View next topic  
Author Message

tchai




Joined: 03 Dec 2018
Posts: 23
Location: NY

View user's profile

Send private message

PostPosted: Dec 03, 2018 20:19    Post subject: What could the locality of this grey fluorite cluster (with small cubic crystals) be?  

Hello all,

This was recently given to me as a gift. The locale is unknown. The translucent grey/black crystals form perfect cubes and have a glassy luster. I was told that this was not dyed or enhanced.

My initial guess was that this is a fluorite specimen since the crystals form such distinct cubes, but I've never seen such dark fluorite before - it still looks dark grey/black in the sunlight, unlike other fluorite I have seen which are usually much more opaque and will look purple under light. Any thoughts are appreciated!



black 1.JPG
 Description:
 Viewed:  2423 Time(s)

black 1.JPG



black 2.JPG
 Description:
 Viewed:  2424 Time(s)

black 2.JPG


Back to top
Reply to topic Reply with quote
Like
3
   

Tobi




Joined: 07 Apr 2009
Posts: 3041
Location: Good Old Germany


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 04, 2018 02:34    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Without a doubt this should be fluorite.
tchai wrote:
but i've never seen such dark fluorite before - it still looks dark grey/black in the sunlight, unlike other fluorite i have seen which are usually much more opaque and will look purple under light. any thoughts are appreciated!
Fluorite occurs in nearly ALL colours and from deep black to bright white. And there's also a wide range from opaque to transparent. But the ones you mention that look purple under (sun)light are quite rare, this is a typical phenomenon of some English fluorites.

Regards
Tobi
Back to top
Reply to topic Reply with quote
Like
1
   

SteveB




Joined: 12 Oct 2015
Posts: 82
Location: Canberra

View user's profile

Send private message

PostPosted: Dec 04, 2018 03:05    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Yep, fluorite. Great gift
Back to top
Reply to topic Reply with quote
Like
   

tchai




Joined: 03 Dec 2018
Posts: 23
Location: NY

View user's profile

Send private message

PostPosted: Dec 04, 2018 08:44    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Thank you for your input! You mention English fluorite - do you happen to know of the specific region they are usually found? I'm just beginning to catalog my collection.
Back to top
Reply to topic Reply with quote
Like
   

Tobi




Joined: 07 Apr 2009
Posts: 3041
Location: Good Old Germany


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 04, 2018 09:40    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

tchai wrote:
thank you for your input! you mention english fluorite - do you happen to know of the specific region they are usually found? i'm just beginning to catalog my collection.
England is, like Germany, a country with a lot of classic fluorite localities, many of them are in Durham, e.g. Rogerley Mine, Blackdene Mine, Boltsburn Mine, Frazer's Hush Mine, Heights Quarry, West Pasture Mine and many many more, another very famous one is Hilton Mine in Cumbria. I recommend further information to get an overview over the variety of English fluorites, here are some links:

https://www.kureczka-martin.com/MinesIntro.htm
https://www.kureczka-martin.com/History.htm
https://www.kureczka-martin.com/Geology.htm
https://www.kureczka-martin.com/Weardale.htm
https://www.kureczka-martin.com/Rookhope.htm
https://www.kureczka-martin.com/Northumberland.htm
https://www.kureczka-martin.com/Cumbria.htm
https://www.kureczka-martin.com/Yorkshire.htm
(Many many MANY!!! detailed information about fluorite mining in England, including plenty of superb descriptions, photos and maps)

https://issuu.com/irocks/docs/greenbank_book_-_complete_reduced
(An eBook about the famous Greenbank collection, including many information about famous British mining regions)

And concerning those fluorites that show purple/blue daylight fluorescence: I think the most famous ones are those from Rogerley Mine, but I'm sure other collectors have more knowledge than me ...

Regards
Tobi
Back to top
Reply to topic Reply with quote
Like
1
   

tchai




Joined: 03 Dec 2018
Posts: 23
Location: NY

View user's profile

Send private message

PostPosted: Dec 04, 2018 09:41    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Thank you again! This is all very helpful information for someone just beginning to study mineralogy.
Back to top
Reply to topic Reply with quote
Like
1
   

Bob Harman




Joined: 06 Nov 2015
Posts: 570
Location: Indiana


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 04, 2018 16:35    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Yours is actually quite a generic specimen. The intergrown fluorite cubes are actually paler in purple color than they look under some lights.

Identical examples come from the mining districts in southern Illinois as well. BOB
Back to top
Reply to topic Reply with quote
Like
   

colin robinson




Joined: 29 May 2013
Posts: 74
Location: Cumbria


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 04, 2018 18:03    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

As an Englishman and collector of fluorites for 50 years I have to say I've never seen anything quite like that from here. I have seen similar material from the U.S. so I'd say Bob's reply is more likely.
Back to top
Reply to topic Reply with quote
Like
1
   

R Saunders




Joined: 28 Jul 2018
Posts: 52
Location: Michigan


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 05, 2018 05:33    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

From my wife's mother.
Fluorite and BARITE
Crystal Victory Mine, Cave-in-Rock, Illinois, USA
756 grams



Flourite (2).JPG
 Mineral: Fluorite and Barite
 Description:
 Viewed:  2161 Time(s)

Flourite (2).JPG


Back to top
Reply to topic Reply with quote
Like
   

Tobi




Joined: 07 Apr 2009
Posts: 3041
Location: Good Old Germany


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 05, 2018 10:23    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

R Saunders wrote:
From my wife's mother.
Fluorite and BARITE
Crystal Victory Mine, Cave-in-Rock, Illinois, USA
756 grams
An interesting specimen, but what has it to do with the mineral ID question in this thread?
Back to top
Reply to topic Reply with quote
Like
1
   

Bob Harman




Joined: 06 Nov 2015
Posts: 570
Location: Indiana


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 05, 2018 10:48    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

As TOBI said, not of meaning in this thread.

This is a piece of massive fluorite and barite (maybe some mixed calcite as well) from the edge of an orebody from the Illinois fluorite district. Classic appearance with no intact crystals of either mineral; just massive.

I might mention that giving the "weight" of these type specimens is really of no importance as it is just a reflection of how "big" your example is. Much more important would be the specimen size, either in inches or centimeters. BOB
Back to top
Reply to topic Reply with quote
Like
   

Kevin Conroy




Joined: 03 Dec 2018
Posts: 50
Location: Saint Louis, Missouri

View user's profile

Send private message

PostPosted: Dec 05, 2018 15:09    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

tchai, please post a picture of the back of the specimen. Sometimes collectors can recognize where it is from by the matrix.
Back to top
Reply to topic Reply with quote
Like
1
   

tchai




Joined: 03 Dec 2018
Posts: 23
Location: NY

View user's profile

Send private message

PostPosted: Dec 05, 2018 16:05    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Sure. This is back of the matrix. Thank you again for all your help!


36773CEB-1D27-4F14-847A-E04DD01059B9.jpeg
 Description:
Fluorite matrix (back)
 Viewed:  2080 Time(s)

36773CEB-1D27-4F14-847A-E04DD01059B9.jpeg


Back to top
Reply to topic Reply with quote
Like
   

Kevin Conroy




Joined: 03 Dec 2018
Posts: 50
Location: Saint Louis, Missouri

View user's profile

Send private message

PostPosted: Dec 05, 2018 20:03    Post subject: Re: Mineral ID Help: cluster of small translucent black cubic crystals - possibly fluorite  

Thank you for the matrix photo. This doesn't look familiar to me, but maybe someone else will recognize it.
Back to top
Reply to topic Reply with quote
Like
   

tchai




Joined: 03 Dec 2018
Posts: 23
Location: NY

View user's profile

Send private message

PostPosted: Jan 17, 2019 20:34    Post subject: what could the locality of this grey fluorite cluster (with small cubic crystals) be?  

hello!

i received conformation via this forum a couple months ago that this piece is indeed fluorite. now i'm trying to figure out what its locality could be.

crystal formation is clearly cubic and the crystals are rather small (the specimen is about 3 in in length and width). color is a gradient from dark to light grey (the zoning is visible in the picture). the crystals are not lustrous; rather, they have the appearance of jelly.

any help is welcome! thanks!



black 2.JPG
 Description:
 Viewed:  1725 Time(s)

black 2.JPG


Back to top
Reply to topic Reply with quote
Like
   

Bob Harman




Joined: 06 Nov 2015
Posts: 570
Location: Indiana


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jan 17, 2019 20:44    Post subject: Re: what could the locality of this grey fluorite cluster (with small cubic crystals) be?  

Fluorite is a very common mineral from numerous worldwide localities. Small inter-grown cubes of grayish purple color, such as yours, are also quite generic. Just from a statistical perspective, your example might be from the southern Illinois fluorite district. A lot of other localities are not excluded.

It sometimes is of help in identifying the localities of these examples is to see the backside matrix of the example. BOB
Back to top
Reply to topic Reply with quote
Like
   

tchai




Joined: 03 Dec 2018
Posts: 23
Location: NY

View user's profile

Send private message

PostPosted: Jan 17, 2019 20:49    Post subject: Re: what could the locality of this grey fluorite cluster (with small cubic crystals) be?  

i've included a picture of the matrix. thanks again for your help, bob!


t_36773ceb_1d27_4f14_847a_e04dd01059b9_570.jpeg
 Mineral: Fluorite
 Description:
The matrix.
 Viewed:  1704 Time(s)

t_36773ceb_1d27_4f14_847a_e04dd01059b9_570.jpeg


Back to top
Reply to topic Reply with quote
Like
   

Bob Harman




Joined: 06 Nov 2015
Posts: 570
Location: Indiana


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jan 17, 2019 21:06    Post subject: Re: what could the locality of this grey fluorite cluster (with small cubic crystals) be?  

Both the fluorite side and the backside matrix suggest the southern Illinois/Kentucky fluorite district, altho other localities are not completely excluded. BOB
Back to top
Reply to topic Reply with quote
Like
   

Jordi Fabre
Overall coordinator of the Forum



Joined: 07 Aug 2006
Posts: 4315
Location: Barcelona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jan 18, 2019 02:48    Post subject: Re: what could the locality of this grey fluorite cluster (with small cubic crystals) be?  

Tchai,

You already asked before for the same thing and with the same photos, and you already got answers
( https://www.mineral-forum.com/message-board/viewtopic.php?p=65004#65004 )

Don't make sense try again the same question, you will get the same answers.
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