Spin-off thread: How much would your stone have to cost in order for you to have it certed?

[Harriet]

Brendaman''s thread raised an interesting issue. Rather than derail her thread, I thought I''d start a new one.

 

[neatfreak]

For me I just don''t really think it''s necessary unless I planned on selling it regardless of how much it cost. I would rather get a very detailed in-depth appraisal from someone like Richard Sherwood instead, and as long as the vendor was willing to stand behind their claims and I knew they were well respected I wouldn''t have a problem buying it uncerted as long as I could return it if it was not as represented.

 

[T L]

Thanks for starting a new thread Harriet. I would want one because even the most trustworthy jeweler/cutter might make mistakes and get heated vs unheated material. I mean how would they know it''s not heated at the mines??? I hope some cutters chime in on this thread to tell me my head needs to be put on correctly

. My feeling is that they have to trust the mine operators as well in that case. I would want a lab report to state that fact, unless Richard Sheerwood has that gemological equipment to make that determination. However, the lab report gives the stone more prestige, and to me that means something, especially if it''s a valuable stone. Even if I''m not planning on selling it, I am going to pass it down to my children, and this gives them something of value. In years to come, even if I know I purchased my stone as an unheated one, this documentation will exist to show that it is what it is.

I think some gems do not need certifications, like those that are not prone to treatments, or at least, intense treatments. Sapphires can be beryllium-heated, rubies lead glass filled, emeralds filled with colored plastic, and the whole nine yards. I think for a fine ruby, sapphire or emerald, I would insist on a lab certification from the AGL, GRS, that states that no evidence of thermal threatment has been identified, or for an emerald, cedarwood oil used only, or something to that effect. For an expensive fancy colored diamond, I would insist on a GIA lab report. For colored diamonds, I don''t think I would want anything less than a GIA report (another lab would not suffice either). I think any stone like a sapphire, ruby or emerald, that costs more than $500/ct would make me want a lab report. There are inexpensive sapphires, rubies and emeralds, and it is not cost effective to want a lab report in those cases.

Now, that being said, I do collect tourmalines, and for those gems, I do not find a lab cert really that necessary. Heating the stones doesn''t make them really lose much value (in fact it can give some stones MORE value). They are typically not a stone that undergoes treatment outside of gentle heat.

 

[coatimundi_org]

If I wasn't able to properly identify treatment on my own, using my own tools, and if it was from a dealer who I had no previous relation--and if it was a potentially valuable stone, then I might get a cert.

With proper tools and relationships with reputable dealers, hopefully an independent appraisal would suffice for insurance purposes. There are many variables for me.

 

[PrecisionGem]

This is an interesting questions, and I''ll comment based on my experience and what a cutter in the USA sees.

First off, unless a cutter travels overseas, or is buying Oregon Sunstone, we are not buying rough directly at the mines. Most of the stones I buy come from Africa, and I have a few trusted contacts there. They buy the stones from people who get them from the mine owners. The miners work for the mine owners, and unless they smuggle stones out, and they do, the mine owners sell the stones to these middle men, who in turn sell them to the dealers in the cities. At the mines, things are not heated. Most of the heating being done is done in Thailand. The Thai''s are in the city buying stones just like the dealers I buy from, the difference being at times they will make an arrangement with the mines to buy everything. This gets them the good facet grade, and all the cab grade and bead grade material, but at a better price since they are taking everything.

So, what happens at times is stones are not identified correctly, or in some cases these middle men will actually put lab created stones into the parcels. The Thai''s are trading large quantities of lab created sapphire for real stones. The Africans then take this lab created material, tumble it, mix it up with dirt and rock, heat it, quench to make it fracture, and when they are done, it looks like real natural stone. They even have colors that are not prefect to make it even more believable.

So the dealer, with his limited equipment, tries to weed these things out, but often he gets taken. Then the cutter can get taken too. So what I do, is when I see a stone that while cutting it, looks too clean, has no needles under the microscope, I question it, and send it in to be tested. In the past few years I have had 3 of these. It''s always a sapphire they are trying to fake out, and usually the stone ends up to be lab created. Sometimes you do get a stone that is not identified correctly. A few weeks back I had a purple sapphire that turned out to be a purple scapolite. This I think was just an honest mistake. These types are things are easy to catch as I have a pretty complete gem lab and test each stone for: Refractive index, Optic sign, pleochroism, birefringence and spectral data. The problem is for some tests the stone needs to be cut, or have a polished surface on it.

There are a lot of fake stones out there, and I would think a lot more in cut goods than in rough. The Chinese are very good at this, so you really need to be careful. A natural inclusion in the stone can prove to be your friend, when you get a stone that is too clean, to perfect color, and you bought it too cheap, there''s a reason. No one in this business gives anything away.

 

[T L]

Wow Gene,
That was very informative. Thank you for that. I did not know they do not heat stones at the mine. I thought they did. At one point, I had thought all emeralds were treated at the mines in Africa and South America. However, heating must be a different story.

 

[chrono]

A lot of good discussion here.

I would get a cert if:
1. It is a commonly treated stone like a sapphire, etc and the stone I am buying has NO treatment. If it's a commonly untreated stone, it'll be a waste.
2. If it costs mega bucks - stuff over $3K

 

[PrecisionGem]

There are some places where heating is done at the mines, I think in Africa it is not that common. I know a guy in China Alex, who mines sapphires, and he does heat them in a 55 gal drum with a fire. The more sophisticated heating is not done at the mine locations.

Emeralds are a different story, they are not heated but filled. Most often with a form of oil or but sometimes other types of resins. This can be done both before cutting and after cutting. Oils can be cleaned out of the stone, and then the stone would require re treating. This one of the reasons you wouldn''t want to put your emerald into an ultrasonic cleaner.

 

[Pandora II]

Date: 12/13/2008 9:01:35 PM
Author: coatimundi
If I wasn't able to properly identify treatment on my own, using my own tools, and if it was from a dealer who I had no previous relation--and if it was a potentially valuable stone, then I might get a cert.

With proper tools and relationships with reputable dealers, hopefully an independent appraisal would suffice for insurance purposes. There are many variables for me.

I'm with you on this.

I was more cautious before my recent buying trip, but having had all the stones I bought checked out by a lab and all but one being what I was sold it as (the one that wasn't I'd bought on the off chance that it really was a spess. and not a hess. as the seller thought - I was right, it was a spess.)

If I was buying stones in the $2k range and up that I planned to resell and that I knew had characteristics that could command a premium (ie unheated sapphire), I'd probably pay for a cert. just so as to add that premium. The majority of buyers are probably au fait with diamond sales techniques and will probably feel happier with a piece of paper with the numbers. A prosumer, once you have established a reputation, is unlikely to be so interested unless it's an important piece.

If they are for my own collection, then I'd generally rather save the $$ and buy more tools - better investment in my book. Unless, you are talking about extreme rarities or stones in the 5 figure range. Then I would feel a certificate was needed.

Definitely wouldn't pay for a cert on any stone under $1k.

 

[T L]

I am so paranoid about rubies, sapphires and emeralds, to me I would want a cert if it was over 1K. 1K is still a significant amount of money to many people, and you don't want to be paying that much for a be-treated sapphire which should go for $20. I guess that's a variable that depends on the person. I definitely would want one at 7K, like the stone Brendaman is considering. I know I mentioned I don't care about tourmalines having a cert, but I have purchased copper bearing tourmalines for a lot of money and they came with a memo stating that they contain copper. That's a bit important to me with tourmalines that cost a signficant amount and are being boasted as cuprians.

 

[canuk-gal]

HI:

We have all seen diamonds with carat weights as small as .25ctw with DQD''s, and depending on the varaibles of that stone, priced under $500. If there is so much variablility (origin, treatments, etc) in colored gemstones doesn''t it beg the question that "most" colored stones should be ID''s in labs? I sense a double standard.

Another question I have related to lab''s and gem "origin" ID; are there labs that do not undertake this task anymore because it can be a contentious issue?

Another random thought--when we were discussing emerald''s here a few years ago, I aksed the question whether it was possible that mines bring in stones from other areas and pass them off as being original to the "famous" mine of that area of purchase......if this is possible and true it makes it even more essential to have the origin of your gems documented. (Brazilian vs. Columbian..etc, etc....).

cheers--Sharon

 

[movie zombie]

great post, Gene!

movie zombie

 

[T L]

Gem origin id's are a whole different ball of wax outside of treatments, and sometimes a lab can determine where a particular stone is from, and sometimes it can't. It depends on the stone and the lab. However if I were to buy a very expensive Burma ruby, to me it would be important to have an origin report, especially if the color was exceptionately fine. Burma rubies have a higher premium than rubies from other parts of the world. Some Madagascar sapphires can look like Ceylon sapphires, would it then be important to have an origin report when it's really the color that defines the value, and not the origin in that case? That's an interesting thing to think about however, and something one might want to consider when purchasing a stone that gets a premium from it's locale.

 

[coatimundi_org]

Date: 12/14/2008 8:50:55 AM
Author: Pandora II

Date: 12/13/2008 9:01:35 PM

Author: coatimundi

If I wasn''t able to properly identify treatment on my own, using my own tools, and if it was from a dealer who I had no previous relation--and if it was a potentially valuable stone, then I might get a cert.


With proper tools and relationships with reputable dealers, hopefully an independent appraisal would suffice for insurance purposes. There are many variables for me.

I''m with you on this.


I was more cautious before my recent buying trip, but having had all the stones I bought checked out by a lab and all but one being what I was sold it as (the one that wasn''t I''d bought on the off chance that it really was a spess. and not a hess. as the seller thought - I was right, it was a spess.)


If I was buying stones in the $2k range and up that I planned to resell and that I knew had characteristics that could command a premium (ie unheated sapphire), I''d probably pay for a cert. just so as to add that premium. The majority of buyers are probably au fait with diamond sales techniques and will probably feel happier with a piece of paper with the numbers. A prosumer, once you have established a reputation, is unlikely to be so interested unless it''s an important piece.


If they are for my own collection, then I''d generally rather save the $$ and buy more tools - better investment in my book. Unless, you are talking about extreme rarities or stones in the 5 figure range. Then I would feel a certificate was needed.


Definitely wouldn''t pay for a cert on any stone under $1k.

Feel the same, Pandora. For my personal collection--more $$ for tools all the way. For reselling, depending on the stone, certs can be a necessity. I''m just starting out and building relationships with dealers, so I''m cautious. But then again, I''m mainly buying commonly untreated stones. It''s good to love garnets.

Thanks for posting that Gene--very informative!

 

[Harriet]

Date: 12/14/2008 10:28:01 AM
Author: canuk-gal
HI:

We have all seen diamonds with carat weights as small as .25ctw with DQD''s, and depending on the varaibles of that stone, priced under $500. If there is so much variablility (origin, treatments, etc) in colored gemstones doesn''t it beg the question that ''most'' colored stones should be ID''s in labs? I sense a double standard.
You''re right, Sharon. There''s an interesting discrepancy.

Another question I have related to lab''s and gem ''origin'' ID; are there labs that do not undertake this task anymore because it can be a contentious issue?
You''re right again.

Another random thought--when we were discussing emerald''s here a few years ago, I aksed the question whether it was possible that mines bring in stones from other areas and pass them off as being original to the ''famous'' mine of that area of purchase......if this is possible and true it makes it even more essential to have the origin of your gems documented. (Brazilian vs. Columbian..etc, etc....).
And again. I''ve been told that there are (were?) 3 mines producing cuprian elbaites in Paraiba. Now, when I see something labelled "old mine Paraiba," that label doesn''t mean much to me.

cheers--Sharon