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
19 Jul-23:41:20 Re: questions regarding collections' photos (Tar4ntula)
19 Jul-11:59:43 Re: new generation for picture - ploum (Ploum)
19 Jul-05:52:50 Re: mineral collages 5.0 (Tobi)
19 Jul-04:33:30 Re: collection of enrique llorens (Enrique Llorens)
19 Jul-04:29:06 Re: collection of tobi (Tobi)
18 Jul-16:39:54 Re: mineral collages 5.0 (Tobi)
18 Jul-15:28:28 Re: favourite barytes? (Dany Mabillard)
18 Jul-15:00:36 Re: collection of firmo espinar (Firmo Espinar)
18 Jul-14:07:04 Re: favourite barytes? (Jose Luis Jara Jara)
18 Jul-13:52:51 Re: favourite barytes? (Niels Brouwer)
18 Jul-13:20:39 Re: don lum collection (Don Lum)
18 Jul-10:30:28 Re: what's up with minfind? (Bob Kerr)
18 Jul-09:12:36 Re: what's up with minfind? (R Saunders)
18 Jul-08:14:56 Re: collection of tobi (Jose Luis Jara Jara)
18 Jul-07:09:41 Re: mineral collages 5.0 (Chris Rayburn)
18 Jul-04:23:28 Re: collection of tobi (Tobi)
18 Jul-01:44:27 The mizunaka collection - zoisite (Am Mizunaka)
17 Jul-19:54:58 Re: what's up with minfind? (Kushmeja)
17 Jul-19:31:02 Re: what's up with minfind? (Monicairocks)
17 Jul-19:21:53 Re: what's up with minfind? (Kevin Conroy)
17 Jul-19:13:24 Re: what's up with minfind? (Turbo)
17 Jul-19:10:14 What's up with minfind? (Bob Kerr)
17 Jul-19:07:38 What's up with minfind? (Bob Kerr)
17 Jul-15:12:01 Re: collection of michael shaw (Michael Shaw)
17 Jul-14:53:31 Re: mineral collages 5.0 (Bob Harman)

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
56897


The time now is Jul 20, 2019 05:03

Search for a textSearch for a text   

A general guide for using the Forum with some rules and tips
Fake Ruby?
  
  Index -> What is it? - Where is it from?
Like
12


View previous topic :: View next topic  
Author Message

Mathias




Joined: 01 Apr 2018
Posts: 96
Location: Vlodrop

View user's profile

Send private message

PostPosted: Jun 02, 2019 09:07    Post subject: Fake Ruby?  

Here's another doubtful specimen; Corundum var. Ruby. Fom India.

I bought the specimen yesterday, from a collector who stopped. He told me that he suspects a fake, glued ruby. I bought it anyway (of course for a bargain).

The size is about 6 cm, left to right, 2 cm thick crystals.

At home I tried to break the crystals apart, but even force didn't split them up.
If these crystals are glued, then the person who did it used incredible strong glue.

There's also no trace of glue visible. So the forger did a wonderful job.

Or could it be that these 2 crystals grew naturally?

Thanks,
Mathias



523E.JPG
 Mineral: Corundum
 Dimensions: 6*5 cm
 Description:
 Viewed:  1100 Time(s)

523E.JPG



523I.JPG
 Description:
 Viewed:  1099 Time(s)

523I.JPG



523G.JPG
 Description:
 Viewed:  1098 Time(s)

523G.JPG


Back to top
Reply to topic Reply with quote
Like
3
   

David K. Joyce




Joined: 15 Dec 2018
Posts: 5
Location: Canada

View user's profile

Send private message

PostPosted: Jun 02, 2019 09:18    Post subject: Re: Fake Ruby?  

Why do you think the join has been faked? Crystals form attached
together all the time. If there is no trace of glue and if the light coloured material is, in fact, mineral. then the two crystals probably formed together. Use a U/V lamp as an additional way to try to detect glue, most of which are fluorescent. DKJ
Back to top
Reply to topic Reply with quote
Like
2
   

Mathias




Joined: 01 Apr 2018
Posts: 96
Location: Vlodrop

View user's profile

Send private message

PostPosted: Jun 02, 2019 09:27    Post subject: Re: Fake Ruby?  

David thanks, I though it was glued because you would expect the crystal edges would be aligned from one to the other crystal. Moreover I could find any photos (google) of similar specimen.
Thanks,
Mathias.
Back to top
Reply to topic Reply with quote
Like
   

Bob Carnein




Joined: 22 Aug 2013
Posts: 146
Location: Florissant, CO

View user's profile

Send private message

PostPosted: Jun 02, 2019 09:41    Post subject: Re: Fake Ruby?  

As suggested by Mr. Joyce, a fluorescence test definitely would help. In the last photo, the crystals appear to be intergrown. It would be very difficult to "fake" this, and it seems doubtful that anybody would attempt it on a specimen that you yourself said was relatively inexpensive. Also, the juncture appears to contain material similar to what's seen in the cracks parallel to the basal pinacoid.on the left-hand crystal. Crystal edges might be aligned if this was a twin, but it may just be a random intergrowth. Note that parting surfaces in the two crystals are also not aligned.
Back to top
Reply to topic Reply with quote
Like
   

Pete Richards
Site Admin



Joined: 29 Dec 2008
Posts: 640
Location: Northeast Ohio


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jun 02, 2019 11:48    Post subject: Re: Fake Ruby?  

The first image does suggest a twinned crystal, though the other two really don't - there is no reason for one half of a twin to show part of a termination adjacent to the twin plane.

Twinning is known in corundum, on {10-11} for those who understand Miller indices. What is important is that true twinn would have a much more acute angle between the two halves. And it might be expected to lead to a distorted shape. Here is a figure from Dana's System, 7th edition, of a twin from South Africa, which shows the proper angle for the twin and also considerable flattening of the crystal due to the effects of twinning on the growth rates of various faces of the crystal.



IMG_5710.jpg
 Mineral: Corundum twin on {10-11}
 Description:
 Viewed:  1023 Time(s)

IMG_5710.jpg



_________________
Collecting and studying crystals with interesting habits, twinning, and epitaxy
Back to top
Reply to topic Reply with quote
Like
4
   

Matt_Zukowski
Site Admin



Joined: 10 Apr 2009
Posts: 619
Location: Alaska


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jun 02, 2019 13:01    Post subject: Re: Fake Ruby?  

Soak it in solvent and see if any glue dissolves.
Back to top
Reply to topic Reply with quote
Like
   

Peter Lemkin




Joined: 18 Nov 2016
Posts: 222
Location: Prague

View user's profile

Send private message

PostPosted: Jun 02, 2019 14:02    Post subject: Re: Fake Ruby?  

Matt_Zukowski wrote:
Soak it in solvent and see if any glue dissolves.


Acetone would do for super-glues. I'd also add I wish I had been offered such for a not-high price! I suspect it is not glued...but since you asked, it is fairly easy to find out. UV and then acetone.
Back to top
Reply to topic Reply with quote
Like
   

David K. Joyce




Joined: 15 Dec 2018
Posts: 5
Location: Canada

View user's profile

Send private message

PostPosted: Jun 02, 2019 15:24    Post subject: Re: Fake Ruby?  

Thanks for that Pete. I've never seen a twinned corundum! DKJ
Back to top
Reply to topic Reply with quote
Like
   

Tobi




Joined: 07 Apr 2009
Posts: 3020
Location: Good Old Germany


Access to the FMF Gallery title=

View user's profile

Send private message

PostPosted: Jun 03, 2019 05:24    Post subject: Re: Fake Ruby?  

I don't have knowledge about twinning and Miller indices, but at least I know that it is not unsual that the rubys from that locality (the name is Mysore, https://www.mindat.org/loc-1999.html ) appear intergrown like that. Most of them are single crystals on matrix or fallen off, but I have seen such aggregates before. So I agree with the others that this is rather natural than fake ...
Mathias wrote:
At home I tried to break the crystals apart, but even force didn't split them up.
I'm glad you failed ;-)
Back to top
Reply to topic Reply with quote
Like
   

Peter Lemkin




Joined: 18 Nov 2016
Posts: 222
Location: Prague

View user's profile

Send private message

PostPosted: Jun 03, 2019 06:13    Post subject: Re: Fake Ruby?  

Tobi wrote:
I don't have knowledge about twinning and Miller indices, but at least I know that it is not unsual that the rubys from that locality (the name is Mysore, https://www.mindat.org/loc-1999.html ) appear intergrown like that. Most of them are single crystals on matrix or fallen off, but I have seen such aggregates before. So I agree with the others that this is rather natural than fake ...
Mathias wrote:
At home I tried to break the crystals apart, but even force didn't split them up.
I'm glad you failed ;-)


Ouch! I, myself, would not have put much force on them in case they were natural. Corundum is very hard and strong, but could have a natural fracture or weak spot. Modern glues can be VERY strong, so I still suggest the UV and acetone before you open the champagne....just to make sure [even if I agree with most here it is likely natural]. Acetone will certainly not hurt the corundum...but do it outside, as it could hurt you breathing it.
Back to top
Reply to topic Reply with quote
Like
   

Mathias




Joined: 01 Apr 2018
Posts: 96
Location: Vlodrop

View user's profile

Send private message

PostPosted: Jun 03, 2019 11:57    Post subject: Re: Fake Ruby?  

I soaked it in Acetone for 30 minutes.
Still rock solid.....
Back to top
Reply to topic Reply with quote
Like
2
   

fuss




Joined: 16 Aug 2018
Posts: 37
Location: Wisconsin

View user's profile

Send private message

PostPosted: Jun 19, 2019 00:01    Post subject: Re: Fake Ruby?  

try a Long wave UV light, should fluoresce brilliant red if its real.
Back to top
Reply to topic Reply with quote
Like
   

Bob Carnein




Joined: 22 Aug 2013
Posts: 146
Location: Florissant, CO

View user's profile

Send private message

PostPosted: Jun 19, 2019 08:52    Post subject: Re: Fake Ruby?  

Synthetic rubies also fluoresce in LWUV.
Back to top
Reply to topic Reply with quote
Like
   

John Betts




Joined: 07 Jun 2012
Posts: 145
Location: New York City

View user's profile

Send private message

PostPosted: Jun 19, 2019 20:48    Post subject: Re: Fake Ruby?  

Using LW or SW UV to detect glues no longer is applicable. Many modern adhesives are UV-curing and they work by absorbing the UV illumination.

I use UV-curing adhesive to restore Herkimer Diamond clusters. Testing with UV does not cause the glue to fluoresce - only inspection under a microscope will reveal the presence of glue.

_________________
John Betts
Back to top
Reply to topic Reply with quote
Like
1
   
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