Discoid fractures and Berylium Treatment

[colorchange]

Hi all,

I have an orange sapphire, bought some time ago that has a very clear discoid fractures caused by heat treatment.
Indeed, I ranked it aquarium gravel (I assumed it to be Be-Treated and I don't deal with Be-Treated ; didn't even felt it was worth going to a lab - it was just part of a lot of medium quality) until I took my magnifying glass and found nothing in it but a very clear discoid fracture.
Now my question is : do very high temperature treatment cause this ? When looking at Be-Treated sapphires usually there is nothing as clear as this.

Thanks

 

[Richard Sherwood]

Date: 3/28/2006 7:00:31 AM
Author:colorchange

I have an orange sapphire, bought some time ago that has a very clear discoid fractures caused by heat treatment.

Indeed, I ranked it aquarium gravel (I assumed it to be Be-Treated and I don't deal with Be-Treated ; didn't even felt it was worth going to a lab - it was just part of a lot of medium quality) until I took my magnifying glass and found nothing in it but a very clear discoid fracture.

Now my question is : do very high temperature treatment cause this ? When looking at Be-Treated sapphires usually there is nothing as clear as this.

Discoid fractures indicate high heat treatment (1600 to 1900 Celsius) in both traditionally heated yellow-orange sapphires and beryllium treated sapphires.

The difference is that the beryllium treated stones are cooked for much longer time periods, usually making a mess of most the inclusions in the stone. Lots of globular or melted looking inclusions. The discoids can have a more melted look to them, often with the center crystal which caused the inclusion melting and "spilling" out in the center area of the discoid.

You can also have this with a traditionally heated high temperature non-beryllium stone though, so it is not a definitive analysis.

If you've got the globular/melted mess going on in the interior of the stone, chances are good it MIGHT be beryllium treated. If you've got an interior with cleaner, crisper temperature modified inclusions and non-spillage within the discoids, then it MIGHT possibly be only traditionally heated.

Further testing would be necessary for a conclusive determination.

 

[colorchange]

Thanks for your answer.

The center inclusion is still well located and unmodified but if it''s not conclusive, as I can''t see anything else inside the sapphire I''ll just drop it back into the tank .
I guess the chances are 99.9% to 0.1% that it be Be-Treated...

 

[Amandas_Jewels]

I have one just like it. I''m not sure if it''s be-treated or heat only - but my guess is it''s be-treated based on the fact it came from Thailand, lol.

 

[colorchange]

Lol, you find everythig in Thailand, from best of the best to synthetic and crap.
But you should have no special confidence and keep in mind that most sellers act like this : when they can sell you crap they will. If you bought it on ebay for instance the chances for Be Treatment against heat only are of 1 000 000 to 1, not minding the seller''s "reputation". (there are also sometimes good stones that are rather cheap but sold certificated ; there are also treated stones sold as unheated with certificate from bad labs - that are choosed mainly for their beeing bad, AIGS costs $15 and is just as good as any Swiss or US lab, why use another one ?)

I have a doubt because all other sapphires in the lot were indeed from Ceylon, not diffused though high temperature heated. Not top fine quality but hey, some jewellers can''t offer 4k€ stones to their clients and are happy with a slightly milky 3.5 Ct "Ceylon blue" sapphire that is heated and $100/Ct ! Some had discoïd fractures too, though undoubtlty not diffused. As I wans''t used to seeing such fractures in Be Treated, I was juist asking .
The problem is that I wouldn''t sell it as "heat only", I don''t sell Be treated and and it''s not worth checking !

 

[Amandas_Jewels]

That''s true, and that''s a good way to be!