Reply from SSEF Swiss Gemmological Institute
Reply from SSEF Swiss Gemmological Institute
With many thanks to Dr. Michael S. Krzemnicki, Director of Swiss Gemmological Institute SSEF for the detailed reply to my letter, and an amazing revelation regarding this strand!
My questions, which hopefully addressed the topics of concern, are in italics.
"Dr. Michael S. Krzemnicki
Today at 9:07 AM
Dear Patricia Saab
My staff member, Dr Laurent Cartier informed me that there is a lively discussion on the pearl-guide.com about the pearl necklace which recently sold at Christie's New York.
Being the director of the laboratory, and having analysed these pearls together with my staff, I would like to answer your questions and help to clarify the situation. Dr Cartier has not tested himself the pearls, but is working as a scientist and project manager at SSEF, therefore I allow myself to answer your questions below.
But first of all, I was quite surprised to see the extent of hypotheses which were drawn from an article by forbes.com, without checking the main resource, the Christie's catalogue of this sale
http://www.christies.com/lotfinder/...6778&sid=24f7ea2f-a7a2-418b-a34e-359881484edb
This would have probably shortened the extensive discussion quite a bit.
Just to summarize. this necklace consists of natural pearls of natural colour. In combination with their beauty, this may explain the world record prize it fetched at the auction.
Concerning your questions:
Were you able to personally examine these pearls, Report 78724, 3 March 2015?
Yes, but as it is the normal procedure at SSEF, there are at least two, but this case finally 4 gemmologists who have worked on these pearls as experts to finalize the result
Can you comment on the age of the clasp versus the age of the pearls? The clasp appears older, and more recently combined with the pearls.
On this we cannot comment, but it is a common practice to restring pearls and to combine them with a new or historic clasp.
How would you determine that this strand is not a mix of naturals, keshi and nonbeaded grafted pearls if they were drilled at the time of examination? Do you examine via xray all pearls or just a sampling? Is it more accurate to identify a natural pearl before drilling?
Pearl testing at the Swiss Gemmological Institute SSEF is based - apart from classical testing with UV light, microscopes etc. - on an advanced testing procedure, including X-ray radiography, X-ray luminescence, X-ray fluorescence, Raman microspectrometry, and in some cases X-ray microtomography and LAICPMS. Based on our expertise and state-of-the-art instrumentation, the SSEF since many years is worldwide the authority for identification of natural pearls, as can been seen when checking back important sales of natural pearls which come along with SSEF reports, e.g.the Peregrina pearl, the pearls from Gina Lollobridgida, the Cowdray natural pearl necklace, etc etc...
Pearl drilling may, in certain cases indeed make pearl identification difficult or even impossible. In cases which are not conclusive due to such a drilling-effect, it is the policy of SSEF to issue no report. However, it has to be said that in many cases, drilling will not completely destroy the internal features of pearls and identification and separation of natural pearls from cultured ones is still very much possible. In fact without this, there would be a major problem in the trade, as most of the pearls (if not freshly from a pearl farm) are drilled, especially historic natural pearls.
Concerning the identity of the pearls in this necklace, we have found internal features in all of these pearl consistent with those of natural pearls, and no such structures known for cultured pearls (e.g. non-beaded aso.)
We recognize that it would take a number of years to collect this many pearls. Is it possible this hoard belonged to a large producer of cultured pearls? If so, this could be why there was no provenance given for the necklace?
Concerning these pearls, they have been certainly collected over many years, as have also seen part of them several times at the SSEF over the years. This is for us very common, as as I said in the first answer, pearls are often restringed and each time need a new report, backed by a testing procedure.
It is not the policy of SSEF to comment on the report about the species of pearls, but based on our analyses, they are not Pinctada margaritifera, but from Pteria Sterna (Baja California), which has produced since centuries, and still is producing natural pearls in quite a quantity (apart from a small pearl farm production).
Do you know and can share approximately how many years it took to collect the pearls?
I cannot comment on this, but certainly this will take many years.
Do you know the species, origin and source of the pearls?
See my answer to question 4.
For those interested to see what SSEF is doing in research on pearls, I suggest the Pearl-Guide readers to check out our website:
www.ssef.ch
In the section Research and publications, there is lots of pearl-related information, including pdf files of presentations and papers about DNA fingerprinting of pearls, age dating of pearls, new pearl farm methods, X-ray microtomography of pearls....
I hope with this, the all open questions are clarified and wish you all the best.
PS: Although I am not often reading the Pearl-Guide, I think it is a perfect platform to exchange news and information and to get excited about pearls, which are for me after so many years of research still a wonder and treasure of nature.
Dr. Michael S. Krzemnicki
Director
Swiss Gemmological Institute SSEF
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SWISS GEMMOLOGICAL INSTITUTE - SSEF The science of gemstone testing?
Aeschengraben 26
CH-4051 Basel / Switzerland
tel. +41 61 262 06 40
fax.+41 61 262 06 41
e-mail:
michael.krzemnicki@ssef.ch
homepage:
www.ssef.ch
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