January 24 Through February 4—TUCSON, ARIZONA: Annual show
Welcome to the GemologyOnline.com Forum
A non-profit Forum for the exchange of gemological ideas
It is currently Thu Mar 28, 2024 2:55 pm

All times are UTC - 4 hours




Post new topic Reply to topic  [ 8 posts ] 
Author Message
 Post subject: Cooking Sapphire with Chrysoberyl
PostPosted: Fri Jun 01, 2007 1:35 pm 
Offline
Gemology Online Übergod
User avatar

Joined: Tue Aug 01, 2006 3:24 am
Posts: 4997
Location: McDonough GA
I bought a sapphire that the vendor says was heated with a parcel of chrysoberyl. Does this count as Be-heating?

Jason


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Jun 01, 2007 2:13 pm 
Offline
Gemology Online Übergod
User avatar

Joined: Mon Oct 17, 2005 2:39 pm
Posts: 3528
Location: San Francisco Bay Area, CA
Well, I think you'll have to assume so unless testing "proves" that there's not Beryllium contamination.

Given that that's how it seems people "discovered" the benefits of Be-treating, the chances are that the presence of the Chrysoberyl substantially affected the change in the Sapphire during heating. It would probably be best to state the stone as Be-treated given the available information.

Now, given that "modern" Be-treatment involves powdered Beryllium for greatest effect/efficiency, and your stone was heated with a parcel of Chrysoberyl stones (presumably not powdered), it is certainly possible that your sapphire was in a region of the crucible that was spared the "taint" of Be... but it would seem prudent to be "sure" before you label the item as "just" heated.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Jun 01, 2007 2:21 pm 
Offline
Platinum Member

Joined: Tue Nov 29, 2005 2:02 pm
Posts: 2646
Only if their was elemental diffusion from the chrysoberyl to the corundum. That would be dependant upon temperature and duration at least.

I think only advanced testing would say for sure. What does the stone look like? Magnification may show signs of high temperature heat, but that alone isn't sufficient evidence to my knowledge.

Many microphotographs of Be treated stones are available, but again....

Immersion might show something, but I believe Be achieves complete penetration into the stone.

I didn't think chrysoberyl was typically heated, so, it sounds as if there was intent anyway.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Jun 01, 2007 3:03 pm 
Offline
Gemology Online Übergod
User avatar

Joined: Tue Aug 01, 2006 3:24 am
Posts: 4997
Location: McDonough GA
I haven't received the stone yet but I can post the vendors pic. To me it really doesnt look as bright as the Be stones I have had in the past. What I have had in the past looks almost so yellow it's fake. At least this stone is believable. It's a tat over 5 carats and will soon be coming to the Specimens forum.

Image


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Fri Jun 01, 2007 3:16 pm 
Offline
Valued Contributor
User avatar

Joined: Sun Oct 16, 2005 4:09 pm
Posts: 140
Location: Oregon
:shock: my heart stopped beating for a moment.

looking forward to seeing your pictures of it... :D
Cat

_________________
And despite all my rage, I am still just a rat in a cage.

The Smashing Pumpkins


Top
 Profile  
Reply with quote  
 Post subject: Re: Cooking Sapphire with Chrysoberyl
PostPosted: Fri Jun 01, 2007 6:10 pm 
Offline
Platinum Member

Joined: Wed Nov 23, 2005 12:47 pm
Posts: 2505
Location: Eastern Europe
brimsjewelry wrote:
I bought a sapphire that the vendor says was heated with a parcel of chrysoberyl. Does this count as Be-heating?

Jason


The intricate technicals are on the thread, but... from a humanistic point of view, if a seller said that, I'd understand that YES, this was Be Treated. Besides, I've heard this phrase used to romance blatantly Be-d sapphires already... so it isn't innocent anymore.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Sun Jun 03, 2007 7:44 am 
Offline
Gemology Online Veteran
User avatar

Joined: Mon Oct 17, 2005 1:06 pm
Posts: 718
Location: Bangkok, Thailand
Hi,
If it was heated with some chrysoberyl then yes it is probably "Be treated". In fact the so called "Be treatment" was discover by a Thai dealer/burner who was working with yellow sapphires from Sri Lanka. In 1995 he found out that when he was heating yellow sapphires with chrysobeyl the result was better. He discovered the process by accident as in Sri Lanka yellow sapphires and yellow chrysoberyls are mixed in gem graverl and he bought many parcels where these 2 stones were mixed. As his knowledge about gems was limitated he used to heat them together. When chrysoberyl was present, the result were better.
From 1995 to 2000 he was heating all his yellow sapphires with chrysoberyls. Then when the huge sapphire deposit of Ilakaka was discovered in 1999 he started working with parcels of yellow and pink stones from this area. The pink stones turned to orangy pink...
These Orangy pink stones were rapidly a hit and were noticed by American gemologist who studied them. They found beryllium inside and also noticed that the stones had an orange rim and a pink center. They were as a result called "Beryllium diffused".

For the small story the Thai Burner refuse to agree that he was heating with chemical and told that he was not using beryllium. For him he was using a gem to help getting better result with the heat treatment of another gem. He refused to give his simple secret to everybody and simply sweared that he was not using any chemicals.
But he learned few days later that Beryllium was a natural component of all chrysoberyls...

Note: yellow sapphire heat treatment using oxydising conditions at very high temperatures was discovered at the beginning of the 1980's and it is probable that many yellow sapphires heated from this time contain in fact some beryllium as probably sapphires and chrysoberyls were mixed during many heating runs before people to understand that Chrysoberyl was improving the process. I remeber several burners telling me that sometimes they were getting reaslly good results without really to understand the reason... May be some chrysoberyls were present in the sapphire parcel. Just to say that potentialy I would not be surprised if somebody could find some "beryllium treated" sapphires in gems bought during the 1980's... 20 years before the official discovery of the so called "beryllium treatment"!

I hope that this historical background will help you to understand that "beryllium treated" or "heated with chrysobeyl" is at the end the same: Some beryllium diffused into the sapphire.

All the best,

_________________
Vincent Pardieu

www.fieldgemology.org
www.conservationgemology.org

The views expressed here are V. Pardieu’s opinions and do not necessarily reflect those of GIA Laboratory Bangkok (http://www.giathai.net)where he is an employee since Dec 2008.


Top
 Profile  
Reply with quote  
 Post subject:
PostPosted: Thu Jun 14, 2007 4:34 pm 
Offline
Gemology Online Übergod
User avatar

Joined: Tue Aug 01, 2006 3:24 am
Posts: 4997
Location: McDonough GA
For those interested here is my pic of the sapphire. It came today.

Jason

Image


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 4 hours


Who is online

Users browsing this forum: No registered users and 17 guests


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 post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Gemology Style ported to phpBB3 by Christian Bullock