Tom Stern's natural pearls

[DrTKStern]

Certifications

Certifications

Hi Slraep,

Unfortunately, CIBJO isn't the only one that will certify just about anything!

http://www.diamonds.net/news/NewsItem.aspx?ArticleID=23227


Gail

Hello,

I want to put in an empirically-based word on this notion that certifications are questionable, with the implication of unreliability. In my opinion, one of the most difficult calls a pearl laboratory must make is whether a pearl is tissue nucleated or natural saltwater, especially when the pearl is of South Sea size and mollusk.

The experiment was this: I sent 40 new pearls to Famous Laboratory A hoping for certification they were natural saltwater pearls worth a small fortune, and in a couple of months, for around $800 received a report that all 40 were tissue nucleated and of little value. I then took the same 40 pearls and sent them to Famous Laboratory B, paid my money, waited, and got back a report that 39 of the 40 were tissue nucleated, while 1 pearl was a saltwater natural.

Although I do not agree with the results, I have to take notice of the 98% concordance rate between labs, blinded. Further, the concordance rate increased my confidence they could actually tell the difference, which I doubt. I twisted and turned, wanting my pearls to be natural, but finally I had to take my medicine...they were not.

My impression is that the labs work seriously and without corruption, so I want to respectfully disagree that labs will certify just about anything, if that was meant to say "whether or not it is true", not just they would take on any material and certify it to the best of their scientific opinion.

If anyone knows of corruption in the labs, please let me know so I can investigate.

Sincerely,
Tom

 

[Pearlgully]

My sarcastic comment was relative only to the "pearl" in the linked article. I thought I was clear as to what my comment addressed. Sorry if you misunderstood.

However, now that you mention it, I seem to remember reading, not that many years ago, that corruption was discovered in one very well known laboratory. The story appeared in several trade publications!

Gail

 

[Slraep]

If anyone knows of corruption in the labs, please let me know so I can investigate.

I erroneously thought the discussion was about the likely misidentification of Nautilus p. pearls; the misuse(I think) of the word "pearl" for non-nacreous lumps; and the persistent astronomical valuations given to old-butt-ugly calcium blobs when there is no one on record ever having paid anything close for one.

Yes, I understand your problem though, Dr. Stern, and I am sure that the minute anyone here discovers corruption by the labs you mention that didn't certify your pearls as naturals, they will immediately contact you to help with your "investigation". Good Luck!

Slraep

 

[Caitlin]

So who is tissue-nucleating salt water pearls? WOW, I think that is big news. Who is selling them? How did that lab even establish criteria for tissue nucleated?

I used to suggest tissue nucleating saltwater pearls, and not one of the experts around here ever ever mentioned them.

If they are "of little value", maybe I could get some. Where are they farmed?

Jeremy knows I want tissue nucleated salt water pearls- why hasn't he brought any home? After all they are solid nacre- who wouldn't want an all nacre SS pearl? Dang. I'm slathering drool for some! I am breathing fire for some! The fire dries up the drool. My avatar, the pearl dragon, is taking over. Watch out!

 

[Pearlgully]

Caitlin,

An article appeared in the Summer 2008 issue of "Gems and Gemology", page 175, entitled "Pinctada Maxima Cultured Pearls Grown Beadless in the Mantle".

The article was discussed on this forum, also. I'm trying to find it.



Gail


P.S. Caitlin, maybe we'll see some in Tucson!

 

[DrTKStern]

I erroneously thought the discussion was about the likely misidentification of Nautilus p. pearls; the misuse(I think) of the word "pearl" for non-nacreous lumps; and the persistent astronomical valuations given to old-butt-ugly calcium blobs when there is no one on record ever having paid anything close for one.

Yes, I understand your problem though, Dr. Stern, and I am sure that the minute anyone here discovers corruption by the labs you mention that didn't certify your pearls as naturals, they will immediately contact you to help with your "investigation". Good Luck!

Slraep

But my point was that I don't believe there is any corruption, and that I was the less informed party.

 

[Slraep]

...one of the most difficult calls a pearl laboratory must make is whether a pearl is tissue nucleated or natural saltwater, especially when the pearl is of South Sea size and mollusk.

Dr. Stern distinctly writes: "of South Sea size and mollusk", and freshwaters cannot possibly come from a SS mollusk. At least not to my knowledge. So they are tissue nucleated saltwater pearls the size South Sea pearls and from their matching molluscs! Oh DOUBLE WOW! South-Sea-sized tissue nuked saltwater pearls!!! I am going to have to fight Caitlin for them! I need to start working out ....

Slraep

 

[DrTKStern]

Tissue Nucleated South Sea

Tissue Nucleated South Sea

So who is tissue-nucleating salt water pearls? WOW, I think that is big news. Who is selling them? How did that lab even establish criteria for tissue nucleated?

I used to suggest tissue nucleating saltwater pearls, and not one of the experts around here ever ever mentioned them.

If they are "of little value", maybe I could get some. Where are they farmed?

Jeremy knows I want tissue nucleated salt water pearls- why hasn't he brought any home? After all they are solid nacre- who wouldn't want an all nacre SS pearl? Dang. I'm slathering drool for some! I am breathing fire for some! The fire dries up the drool. My avatar, the pearl dragon, is taking over. Watch out!

I have them. I'm on a mission to find out from whence they came. These are huge South Sea sizes, remarkable, so much like a hand only of God pearl, without the hand of man. Since no one can tell me where this is being done, and since it is my men bringing them to me with parcels of naturals, I just cannot stop wondering if they indeed might be naturals, and that the lab criteria are inaccurate. That was my point about the 98% agreement between 2 labs, which makes me believe they have some diagnostic technique that can reliably make the determination. This goes against my theory. They have certified many, many pearls as natural.

These tissue nucleated South Sea have profound chatoyance, because of their ultra-thick nacre. Sometimes there is a central cavity about 20% of the volume, the rest nacre.

Best,
Tom

 

[Slraep]

These tissue nucleated South Sea have profound chatoyance, because of their ultra-thick nacre. Sometimes there is a central cavity about 20% of the volume, the rest nacre.

What??? Ultra-thick nacred pearls have a profound chatoyance?? I thought the optical effect described as "chatoyance" was found on non-nacreous pearls exhibiting a flame pattern.(??????)---like a conch or melo. Doesn't ultra-thick nacre gives extraordinary iridescence and orient??? I've never seen an ultra-thick nacre exhibit any type of "cat's eye" effect.

Slraep

 

[Pearlgully]

Dr. Stern,

Could these pearls be just South Sea Keshis that are harvested from the gonad of the mollusk or are the pearls harvested from the mantle of the mollusk, as mentioned in the G&G article in a previous post?

Are they shaped like a South Sea baroque or a freshwater baroque (as in salt water mantle tissue nucleation)?

Gail

 

[pattye]

Doesn't ultra-thick nacre gives extraordinary iridescence and orient??? I've never seen an ultra-thick nacre exhibit any type of "cat's eye" effect.

Sorry to say I won't be in Tucson this year, but perhaps Caitlin and others will be able to check out these pearls in person for us. Last year Caitlin and I spent several hours looking at Dr. Tom's gorgeous pearls and visiting with him and his wife, Yolanda, mostly about pearls! Caitlin photographed as many of the pearls as possible. Dr. Tom has access to some of the most remarkable pearls I have ever seen in person! The pearls in question hopefully can be discussed here more fully. I evidently missed any previous mention of the article about tissue nucleated SS.

 

[GemGeek]

Must be some serious interference color going on to give a shifting eye. Cool.

 

[DrTKStern]

Dr. Stern,

Could these pearls be just South Sea Keshis that are harvested from the gonad of the mollusk or are the pearls harvested from the mantle of the mollusk, as mentioned in the G&G article in a previous post?

Are they shaped like a South Sea baroque or a freshwater baroque (as in salt water mantle tissue nucleation)?

Gail

They definitely exhibit "water" which is what I may be mistakenly calling chatoyance. They are certified as tissue nucleated saltwater, and they come in a variety of shapes and sizes. I don't know what part of the animal they come from; and I continue to have my doubts whether they are cultured at all.

I also have enormous South Sea Keshi; but I'm wondering how they would differ from what 3 labs have called Tissue Nucleated. Can you expand on that distinction?

I think in Gems and Gemology this month there is mention of some new testing by Gubelin, but I'm not sure this bears precisely on the question.

Regards,
Tom

 

[DrTKStern]

What??? Ultra-thick nacred pearls have a profound chatoyance?? I thought the optical effect described as "chatoyance" was found on non-nacreous pearls exhibiting a flame pattern.(??????)---like a conch or melo. Doesn't ultra-thick nacre gives extraordinary iridescence and orient??? I've never seen an ultra-thick nacre exhibit any type of "cat's eye" effect.

Slraep

Caitlin looked at some pearls of mine last year and taught me how to see this "water" phenomenon. Caitlin? Didn't you call it chatoyancy?

Best regards,
Tom

 

[DrTKStern]

Sorry to say I won't be in Tucson this year, but perhaps Caitlin and others will be able to check out these pearls in person for us. Last year Caitlin and I spent several hours looking at Dr. Tom's gorgeous pearls and visiting with him and his wife, Yolanda, mostly about pearls! Caitlin photographed as many of the pearls as possible. Dr. Tom has access to some of the most remarkable pearls I have ever seen in person! The pearls in question hopefully can be discussed here more fully. I evidently missed any previous mention of tissue nucleated SS.

Hi,

Never recall mentioning them before. Am most interested in what everyone knows about such things!

Best regards,
Tom

 

[Jnorris]

Hello everyone.
I would like to reissue the challenge. Can anyone owning a "Nautilus Pearl" show me a shell exhibiting the flame pattern as seen in the photo provided on this thread. I must disagree with the Calcareous lump comment. Certainly all pearls can not be defined by the properties of an Oyster pearl.
I do not believe that there is any intentional misidentification with in the Laboratories but I know that it sometimes happens. Does anyone else believe this might be the case with the Nautilus pearls.

 

[pattye]

Dr. Tom, sorry, I didn't mean you mentioned them, just posts here on the forum in general about tissue nucleated SS.

 

[pattye]

I also have enormous South Sea Keshi; but I'm wondering how they would differ from what 3 labs have called Tissue Nucleated. Can you expand on that distinction?

Last year I purchased 3 good sized white SS keishi from Dr. Tom. When I held them up to bright light here at home I could see the large dark "worm" in the center. My understanding is that in a tissue nucleated pearl the small piece of tissue is pretty much "absorbed" somehow as the nacre is laid down. Or if there is any left in the center of the pearl, it would be a small amount. I suppose when the pearl is drilled, one would have a clue whether tissue nucleated or keishi by the smell!

 

[Pearlgully]

I am having difficulty posting the link to the thread where we discussed the G&G article, so I will do my best to direct you to it: it's under the "Pearling Industry News" forum and the thread is "Pintada Maxima Cultured Pearls Grown Beadless in the Mantle" on 8/4/08.

More importantly, this G&G issue can still be purchased from the GIA website. It is Volume XLIV / Summer 2008.


Gail

 

[pattye]

Thanks, Gail! I will try for the link--https://www.pearl-guide.com/forum/pearling-industry-news/2871-pinctada-maxima-cultured-pearls-grown-beadless-mantle.html