Post subject: traces of be treated yellow sapphire
Posted: Fri Feb 10, 2006 1:26 am
Valued Contributor
Joined: Thu Jan 26, 2006 5:50 am Posts: 163 Location: Shandong, China
Hi all,
I appreciate all the replies and discussion on the be treatment issue which enabled me to know in depth backgrouds and harms done on the sapphire market.
Now even in the shandong sapphire mine here, I have to be extremely careful as not sure whether the yellow rough is one brought back from Chantaburi being be-treated. Dare not buy the usually large pieces!
The other day, a local cutter was trying to sell me hundreds carats of yellow sapphires as we also make sapphire jewelry. Though we cut yellows ourselves, I can't believe he can cut so many yellows as yellow roughs are scarce. So I got a few pieces, telling him for sample purpose.
Among the lot, 80% are very clean with nice honey to orange yellow. But then I saw these 3 pieces. I immersed them in water and the greenish black spots are clearly visible.
I suspect these will be the evidence of unmelted berylium powder. Can the gemologists on this forum confirm on this? Maybe you already know but maybe it's not bad for those who don't know.
Joined: Mon Oct 17, 2005 10:20 am Posts: 186 Location: MONTANA
page 114 or richard hughes book ruby and sapphire states on heat treated sri lanken yellow ,orange reddish orange sapphires heat treatment---
" often rendering it slightly cloudy or silky in the process.. " "these heated sapphires are strongly zoned , with the most intensly colored regions displaying the the greatest consentration of mineral particles"
he may mean tiny inclusions "exsolved particles" in the gem... his book would be a good starting point for learning all about sapphires, thier treatments, and other facts about rubys and sapphires.. it is not cheap but considering the money spent on travel and purchaseing sapphires it would be a good investment.. ... hughes goes on to state that "most of the heat treated gems hes seen of these colors shows thesse characteristics"
i would check this, if the gems you have bought do display these colors..
in your photo, the lower gems long finger like inclusion probably would have exploded during heat treatment tho.. the green spots if on the inside would not be be treatemnt as i think the be treatment would be on the outside of the gems.. normaly treaters dont do included stones as they tend to explode when they get hot.. gerus please correct me if im wrong or making poor observations.. dave
Hi,
These green or blue spots are typically rutile rich crystals from which some titanium has diffused out during high temperature heat treatment.
The presence of such crystal inclusions surrounded by strongly colored halo has never been seen in unheated stones.
These inclusions are very strong indications that the stone was heated at hight temperature probably using some beryllium or may be other light elements as you can see in the following photo gallery:
http://www.fieldgemology.com/showpic.php?sub_id=44&type=lab
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.
Joined: Fri Jan 27, 2006 12:27 pm Posts: 764 Location: Western NY
Anyone have a cheap sample of Be treated stones with the inclusions Alex's show? I'd love to have a reference stone or two. Vincent's pics are fantastic, but I'd really like to be able to study the stone under a scope.
Post subject: traces of be treated yellow sapphire
Posted: Sat Feb 11, 2006 5:14 am
Valued Contributor
Joined: Thu Jan 26, 2006 5:50 am Posts: 163 Location: Shandong, China
Thanks Vincent for your great information. Like what the ancient Chinese saying goes, a master's few words is more than 10 years hard study by yourself. A comprehensive gemological study will be worthwhile for me. Though hundreds of kilos sapphires have been mined and checked through my hands, I can only judge from my experience which could be wrong in many cases.
And if you ever decide to be in the Shandong sapphire mine for a field trip, be my guest.
Joined: Mon Oct 17, 2005 2:52 pm Posts: 241 Location: France | French Riviera
vincent pardieu wrote:
Hi, These green or blue spots are typically rutile rich crystals from which some titanium has diffused out during high temperature heat treatment. The presence of such crystal inclusions surrounded by strongly colored halo has never been seen in unheated stones. These inclusions are very strong indications that the stone was heated at hight temperature probably using some beryllium or may be other light elements as you can see in the following photo gallery: http://www.fieldgemology.com/showpic.php?sub_id=44&type=lab
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