GRS Alert: Warnings of Some Mozambique Rubies

[pajero_exceed]

http://www.gemresearch.ch/news/2014-12-22_WarmingAlert/index.htm

 

[minousbijoux]

I would think one safeguard from this would be the photo of the stone on the GRS report; if anyone tampers with the stone post report, If done successfully, the appearance of the ruby in hand will be significantly different that what is on the report...

 

[Marlow]

These vendors don't understand that they destroy their buiness!!!

It is a serious problem for trade persons buying in bangkok and selling them with an "old" report.

Think gentle heat to get a better color is o.k. but I want to know it and pay for a heated stone.

 

[pajero_exceed]

How the low temprature heat can improve the stone's appearance? Does the same thing happen to Burmese rubies? Appreciated it if anybody could explain it.

 

[LoversKites]

I would think one safeguard from this would be the photo of the stone on the GRS report; if anyone tampers with the stone post report, If done successfully, the appearance of the ruby in hand will be significantly different that what is on the report...

Exactly what a friend of mine said when I told him about the issue. Wouldn't the colour stated be significantly different too?

 

[LoversKites]

How the low temprature heat can improve the stone's appearance? Does the same thing happen to Burmese rubies? Appreciated it if anybody could explain it.

You should start a new thread with these questions, they are interesting and deserve to be discussed properly.

How heat improves colour I am not sure (as in, what happens/changes in detail). Heating can occur in rubies from any origin, yes.

 

[Marlow]

Heating Rubies with a "low temperature" removes an undesirable hue.

So unheated versus heated with better color

So you finally get a heated stone with a bit better color and a report for an unheated stone --> +++$$$$$ !!!

 

[Marlow]

And forget a picture!

If heating removes a very slightly violet hue you have no chance to see the difference in a picture. You need a fresh report - I would send it again to a lab.

 

[minousbijoux]

Heating in Mozambique rubies can drive off brown. Heating in other corundum can melt some inclusions increasing the clarity and sparkle of stones. In the case of blue sapphires, heat can improve the color by - I believe - lightening and intensifying the blue of an overly dark stone. I'm sure there are many other effects of heating at low temperatures; these are a few that come to mind that I'm aware of. High heat, diffusion and introduction of foreign elements is a whole other discussion with radically different results.

 

[minousbijoux]

And forget a picture!

If heating removes a very slightly violet hue you have no chance to see the difference in a picture. You need a fresh report - I would send it again to a lab.

Ah, I see. I was thinking that the change brought about by low heat would be substantial enough to make a visible difference - one that would then call into question the photo in the GRS (or other lab's) report. I agree that if its a subtle change, we are all pretty much screwed, unfortunately.

 

[Marlow]

Yeah, I think they use very low temperature - the inclusions except gas filled will look undamaged - unfortunately some are really "artist" - and of course they will use the "right" gems!!

IMO a problem for a vendor buying and selling stones in Bangkok - and finally we buy this treated stone and will have a discussion with the poor vendor! Both are victims!

Would be interesting to hear Mr Hughes - he has a new lab spec. in ruby and sapphire....

Buying corundum is no fun.

I want to pay a fair price - I don't care whether a ruby is unheated or low heat.

 

[LoversKites]

Ok, I understand it now. It's unfortunate.

 

[T L]

Buying corundum is no fun.

I think sapphires are safe to buy for the most part, but rubies, forget about it. . .

which is why I don't own any.

 

[Sunstorm]

Wow, there is alway some sort of a new scam that surfaces and is very hard to detect. Thanks for bringing it to our attention! I think that though we are talking about Mozambique rubies here, if I wanted to pay a very high price for an untreated corundum, whether rubies or sapphires of top color and quality in general, I would want to have the stone tested fresh and preferably myself and make the sale contingent on that. It is just a dangerous market these days for rubies especially. I do agree that sapphires are safer but they have also become much scarcer in top quality unheated. Rubies are an entirely different story, finding them in top quality, unheated gemstones is almost impossible. And on today's market pretty much all you can find even then is Mozambique unless you somehow get a chance to buy an old stone. Yeah, it is not even that there is anything wrong with heated but a customer paying a fair price is the key here. Great thread, thanks for the heads up again. Have not heard about this one yet.

 

[LD]

I agree that photos won't help. The difference can be minor and difficult to detect from a photo and we all know how bad some photos are! What a shame that people are being duped like this

 

[pregcurious]

Thanks for the article. Buying high priced stones in general is scary. I decided not to buy any more high priced colored stones a few years ago.