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
18 Mar-08:12:52 Green seam. Looks like it in a state of decay. (Ning)
18 Mar-06:47:13 Mineralogy & museums 10 - cardiff - 12th-13th august 2024 (Roy Starkey)
18 Mar-02:50:32 Re: collection from dany mabillard (Dany Mabillard)
17 Mar-01:57:58 Re: collection of volkmar stingl (Volkmar Stingl)
15 Mar-14:27:47 Re: collection of philippe durand (Philippe Durand)
15 Mar-13:49:04 Re: collection of firmo espinar (Firmo Espinar)
15 Mar-09:18:42 Re: collection of michael shaw (Michael Shaw)
15 Mar-03:45:43 The mizunaka collection - rhodochrosite (Am Mizunaka)
14 Mar-21:29:31 Re: monthly mineral chronicles, mineral guides and more... (Crocoite)
14 Mar-14:47:27 Re: collection of philippe durand (Jordi Fabre)
14 Mar-13:56:01 Re: collection of philippe durand (Philippe Durand)
14 Mar-11:24:43 Re: collection of philippe durand (Jordi Fabre)
14 Mar-08:55:22 Re: collection of michael shaw (Michael Shaw)
14 Mar-08:44:47 Re: the mim museum in beirut, lebanon (Mim Museum)
14 Mar-07:24:12 Re: collection of volkmar stingl (Volkmar Stingl)
14 Mar-02:30:15 The mizunaka collection - quartz (Am Mizunaka)
14 Mar-02:20:37 Re: collection of volkmar stingl (Tobi)
13 Mar-23:40:08 Re: collection of volkmar stingl (Volkmar Stingl)
13 Mar-14:22:58 Re: don lum collection (Don Lum)
13 Mar-14:02:43 Re: collection of philippe durand (Philippe Durand)
13 Mar-00:57:48 The mizunaka collection - quartz (Am Mizunaka)
12 Mar-07:36:06 Re: can you recommend a lab to analyse specimens (Luiz Oliveira)
11 Mar-16:19:18 Re: collection of philippe durand (Riccardo Modanesi)
11 Mar-15:18:26 Re: collection of philippe durand (Philippe Durand)
11 Mar-15:13:07 Re: collection of philippe durand (Philippe Durand)

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
111630


The time now is Mar 18, 2024 21:08

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.
Any Ideas?
  Goto page 1, 2  Next
  Index -> FOR BEGINNERS: What is it? Where is it from?
Like
4


View previous topic :: View next topic  
Author Message

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 28, 2022 02:57    Post subject: Any Ideas?  

May 2022
Arkansas
Specific Gravity 3.88-3.94
6.9 grams
Sapphire?
Unusual?



915B4089-3BFB-495C-ADFB-236C5DB5C367.jpeg
 Description:
 Viewed:  11288 Time(s)

915B4089-3BFB-495C-ADFB-236C5DB5C367.jpeg



64705F93-C5AA-499B-ACD4-C5FFB2685274.jpeg
 Description:
 Viewed:  11276 Time(s)

64705F93-C5AA-499B-ACD4-C5FFB2685274.jpeg


Back to top
Reply to topic Reply with quote
Like
   

James Catmur
Site Admin



Joined: 14 Sep 2006
Posts: 1336
Location: Cambridge


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 28, 2022 05:58    Post subject: Re: Any Ideas?  

Test the hardness (#8) and reaction to acid (#10). The SG looks to be a bit low for Corundum.

https://www.mineral-forum.com/message-board/viewtopic.php?p=19487#19487
Back to top
Reply to topic Reply with quote
Like
   

Peter Megaw
Site Admin



Joined: 13 Jan 2007
Posts: 961
Location: Tucson, Arizona


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 28, 2022 09:43    Post subject: Re: Any Ideas?  

Looks somewhat like a diamond macle
_________________
Siempre Adelante!
Back to top
Reply to topic Reply with quote
Like
1
   

Bob Morgan




Joined: 18 Jan 2018
Posts: 226
Location: Savannah, Georgia


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 28, 2022 11:17    Post subject: Re: Any Ideas?  

Although the specific gravity is high for calcite, perhaps that's what it is. Try an acid test.
Back to top
Reply to topic Reply with quote
Like
   

James Catmur
Site Admin



Joined: 14 Sep 2006
Posts: 1336
Location: Cambridge


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 28, 2022 11:31    Post subject: Re: Any Ideas?  

Not impossible for Arkansas. But SG is a bit too high

Peter Megaw wrote:
Looks somewhat like a diamond macle
Back to top
Reply to topic Reply with quote
Like
   

Riccardo Modanesi




Joined: 07 Nov 2011
Posts: 618
Location: Milano

View user's profile

Send private message

PostPosted: Dec 28, 2022 11:41    Post subject: Re: Any Ideas?  

Hi to everybody!
SG is a little low for corundum and a little too high for diamond, even if the appearance is typical for the latter one. Agree with who advices to try with an acid test, and I can add: try the hardness too, with iron, with glass and with anything else.
Greetings from Italy by Riccardo.

_________________
Hi! I'm a collector of minerals since 1973 and a gemmologist. On Summer I always visit mines and quarries all over Europe looking for minerals! Ok, there is time to tell you much much more! Greetings from Italy by Riccardo.
Back to top
Reply to topic Reply with quote
Like
   

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 28, 2022 12:04    Post subject: Re: Any Ideas? Many thanks..  

Thank you all so very much for your time, and interest and mostly advice!

It is a privilege to be able to reach out to folks who have a passion, and bear knowledge without rights. That you share, is just plain awesome.

I don’t get to explore much as I like, and takes me an even longer to go through what I can pick up in just a minute. Always something new, ever time.

I’ll read through the tests 8 and 10 and do those. Let you all know soon as I get results. My SG was the lower one day I tested under a low front, and the other it was sunny and bright. Who wants to guess? I bet most of y’all would be correct.

My tools are ok for it I suppose. My gram scale reduces to .0 of a gram one digit in my favor to see .00. I tried my best to add nothing to the weight in water. I superglued a fishing line to it to suspend it. That’s life here on the river, just up out the bottoms on the right :)

Beautiful day! Be a blessing, seek peace and may you know that the Lord Jesus.. walks beside you.
Back to top
Reply to topic Reply with quote
Like
   

Firmo Espinar




Joined: 05 Apr 2017
Posts: 751
Location: Medellín, Colombia.


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 28, 2022 19:33    Post subject: Re: Any Ideas?  

Hi everyone.

Another vote for some kind of corundum due to its pseudo hexagonal shape perimeter.
Back to top
Reply to topic Reply with quote
Like
   

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 28, 2022 23:26    Post subject: Re: Any Ideas?  

Couple of scratch tests done. I tried it with a glass bead reamer (jeweler tool) which is diamond coated (claimed) and I can as expected scratch it with that, however it’s almost as if you can see where the test, but it didn’t really look to have done anything?? If that makes any sense. Also on unglazed white ceramic (mortise) it left no visible streak, so it clear to opaque to white.

Acid…is there any substitute for what to use, time adjustment? I have a cleaning product that is 10%hcl. If no then I will phone a friend :) Not near any hobby store for miles around.

I hope it is okay to post new pictures, since they are directly on subject. Wanted to share transparency.

Thanks again

PS it dug a rut through heavy mag glass lens



79947632-8478-46E2-8943-B5F6839E3397.jpeg
 Description:
 Viewed:  10963 Time(s)

79947632-8478-46E2-8943-B5F6839E3397.jpeg


Back to top
Reply to topic Reply with quote
Like
   

James Catmur
Site Admin



Joined: 14 Sep 2006
Posts: 1336
Location: Cambridge


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 29, 2022 04:04    Post subject: Re: Any Ideas?  

It looks like it is harder than glass but not as hard as diamond. That rules out Calcite so the acid test should do nothing.

With the crystal growth patterns, Corundum is a possibility. Where did you find it ('Arkansas' is a large area)?

Corundum is reported from Lake Catherine

https://www.mindat.org/loc-286741.html

James
Back to top
Reply to topic Reply with quote
Like
   

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 29, 2022 05:39    Post subject: Re: Any Ideas?  

James Catmur wrote:
It looks like it is harder than glass but not as hard as diamond. That rules out Calcite so the acid test should do nothing.

With the crystal growth patterns, Corundum is a possibility. Where did you find it ('Arkansas' is a large area)?

Corundum is reported from Lake Catherine

https://www.mindat.org/loc-286741.html

James


Yes, it is a large area, I understand. I brought it home in a bucket I carried out while on a trip to the Crater of Diamonds State Park. I’m sure it is going to be corundum but it’s so close (looks like a diamond, the trigons, it’s hydrophobic, it’s cold, it’s lustrous). Another thing also - it has other smaller crystals within. Some red, green, black. I’ll set up to take some pictures through my reverse telescope lens setup so you can see them. It’s a cool little stone. Thanks, and I’ll keep updating. I can’t find anyone around here that works with rough stones… I’ve heard stories of people dropping stones on the ground at the park that are not native to there.
Back to top
Reply to topic Reply with quote
Like
   

James Catmur
Site Admin



Joined: 14 Sep 2006
Posts: 1336
Location: Cambridge


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 29, 2022 07:03    Post subject: Re: Any Ideas?  

People 'salt' with non-local stones. That may well be what you have, so who knows where it is from. Hardness-wise and crystal form-wise it suggests Corundum but it could be a diamond given the location.
Back to top
Reply to topic Reply with quote
Like
   

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 29, 2022 11:01    Post subject: Re: Any Ideas?  

James Catmur wrote:
People 'salt' with non-local stones. That may well be what you have, so who knows where it is from. Hardness-wise and crystal form-wise it suggests Corundum but it could be a diamond given the location.


Salt..that’s so fitting. I’ll surely remember that one!
Just curious, everyone told me to get a thermal conductivity meter. No one here has mentioned it. Are they reliable? In the case of one of those, could there be false positives? Idk how much they are, but if they are not reliable enough then I don’t see the point.
Back to top
Reply to topic Reply with quote
Like
   

alfredo
Site Admin



Joined: 30 Jan 2008
Posts: 977


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 29, 2022 12:00    Post subject: Re: Any Ideas?  

Don't waste your money on a thermal conductivity "diamond tester". They are designed for use on the flat polished facets of gemstones and give very unreliable results on rough stones and crystals.
Back to top
Reply to topic Reply with quote
Like
   

James Catmur
Site Admin



Joined: 14 Sep 2006
Posts: 1336
Location: Cambridge


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 29, 2022 12:07    Post subject: Re: Any Ideas?  

Read this:

http://www.johnbetts-fineminerals.com/jhbnyc/diamondtest.htm

Visit a local jewellery store and ask them to test it, or talk to the Park staff is it is big for the diamonds found there

James
Back to top
Reply to topic Reply with quote
Like
   

Peter Lemkin




Joined: 18 Nov 2016
Posts: 398
Location: Prague

View user's profile

Send private message

PostPosted: Dec 29, 2022 12:49    Post subject: Re: Any Ideas?  

I'd hazard corundum - but nowhere do I see you state the size. The photos only imply what the size may be. For a diamond in that location it is too big and I don't think they have ones like that but you can see here https://www.mindat.org/gallery.php?frm_id=pager&cform_is_valid=1&min=1282&loc=&u=&potd=&pco=&d=&showtype=1&phototype=0&checkall=0&filtmin=0&filtassoc=0&filtcountry=USA&loctxt=arkansas&keywords=&orderxby=0&submit_pager=Filter+Search
Back to top
Reply to topic Reply with quote
Like
   

James Catmur
Site Admin



Joined: 14 Sep 2006
Posts: 1336
Location: Cambridge


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 29, 2022 12:58    Post subject: Re: Any Ideas?  

6.9 grams or, were it a diamond, almost 35ct! So size suggest a corundum

Peter Lemkin wrote:
I'd hazard corundum - but nowhere do I see you state the size. The photos only imply what the size may be. For a diamond in that location it is too big and I don't think they have ones like that but you can see here https://www.mindat.org/gallery.php?frm_id=pager&cform_is_valid=1&min=1282&loc=&u=&potd=&pco=&d=&showtype=1&phototype=0&checkall=0&filtmin=0&filtassoc=0&filtcountry=USA&loctxt=arkansas&keywords=&orderxby=0&submit_pager=Filter+Search
Back to top
Reply to topic Reply with quote
Like
   

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 29, 2022 13:57    Post subject: Re: Any Ideas?  

alfredo wrote:
Don't waste your money on a thermal conductivity "diamond tester". They are designed for use on the flat polished facets of gemstones and give very unreliable results on rough stones and crystals.


Good info..thank you very much
Back to top
Reply to topic Reply with quote
Like
   

Shanester




Joined: 15 Dec 2022
Posts: 11
Location: Arkansas

View user's profile

Send private message

PostPosted: Dec 29, 2022 14:07    Post subject: Re: Any Ideas?  

Peter Lemkin wrote:
I'd hazard corundum - but nowhere do I see you state the size. The photos only imply what the size may be. For a diamond in that location it is too big and I don't think they have ones like that but you can see here https://www.mindat.org/gallery.php?frm_id=pager&cform_is_valid=1&min=1282&loc=&u=&potd=&pco=&d=&showtype=1&phototype=0&checkall=0&filtmin=0&filtassoc=0&filtcountry=USA&loctxt=arkansas&keywords=&orderxby=0&submit_pager=Filter+Search


6.9 grams :)
Back to top
Reply to topic Reply with quote
Like
   

Josele




Joined: 10 Apr 2012
Posts: 405
Location: Tarifa, Spain


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Dec 29, 2022 15:08    Post subject: Re: Any Ideas?  

Looks like a water worn piece of colorless corundum found in a placer deposit. Measured SG fits corundum and trigons on basal pinacoid faces also fits.

Is not so rare find relocated specimens far away from its origin for a variety of reasons, someones really amazing.

A specimen quite similar to Shanester piece.



P1210771.jpg
 Mineral: Corundum
 Locality:
Mysore District, Karnataka, India
 Dimensions: 4 x 4 x 1.2 cm
 Description:
Mysore corundum sample with trigons on basal pinacoid faces
 Viewed:  10676 Time(s)

P1210771.jpg


Back to top
Reply to topic Reply with quote
Like
3
   
Display posts from previous:   
   Index -> FOR BEGINNERS: What is it? Where is it from?   All times are GMT - 5 Hours
Page 1 of 2
  Goto page 1, 2  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 2006-2024


Powered by FMF