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Natural Pearls/which type of xray? Bonhams asked for it

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  • #16
    Originally posted by Orient View Post
    Dentist X-ray units and medical ones in general are not really good for pearl work (only some obvious bead cultured ones). You need something more semi-conductor related or designed for the specific job at hand. Externally I would say that the jeweller who stated your pearls were cultured is the correct one, but the X-rays will tell whoever has experience the final result. If you are going to spend money on testing it may be better to do some homework on the main labs and the fees they charge before adding on shipping/insurance costs too. If you can wait for a visit to any country that happens to have a lab and submit the pearls then it will save you some of the costs. Depends how much of a hurry you are in to have them identified! Bonhams will likely only accept the ID from certain labs too, so best to be sure which they would accept. Good luck.
    The place the necklace will be brought is a research centre including gemstones.It's a main lab. But I am not sure that they are qualified in pearls. That's the main concideration.

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    • #17
      Originally posted by Caitlin View Post
      I hope it does not cost too much, because those pearls have no nucleus to give them away. Rather, a test for saltwater/freshwater origin would be more practical. An x-ray will tell you nothing - unless they are saltwater. If so, then get the xray to sell them at Bonhams.
      Caitlin's point is important, though. You will need them tested for saltwater vs. freshwater. If there is no nucleus to be seen, will your mother then decide they are wild/natural saltwater pearls when they could be cultured freshwater pearls that do not have a nucleus?

      - Karin

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      • #18
        Originally posted by lemanmls View Post
        God save anyone from her rage
        I'd say it sounds like a case of good luck to your jewellery maker and the lab!!
        Let's hope they are up to the task your Mum expects from them!
        I am no expert but am enjoying learning from this post.
        All the best!
        Happy Huku
        Queensland
        Australia

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        • #19
          Please bear in mind that, since your jeweler was the intermediary, he could have been cheated as well and the original seller was the one who was passing off cultured pearls for natural, if the pearls turn out to be cultured.
          Contemporary Jewelry by Beatriz Fortes
          My blog

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          • #20
            This thread is so interesting. I have to agree with Caitlin though that a freshwater vs. saltwater is more appropriate. The thing about your pearls lemanmis is they are not big, therefore, there will likely be no bead inside. 2nd, it's quite an old strand so whether natural or cultured, the tissue nucleus would have shrunk or decomposed over time and would most likely leave a void inside the pearl. It's really the most difficult thing and might be next to impossible to determine natural vs. cultured on old, small freshwater pearls. Also that is a lot of pearls for a natural strand with seemingly uniform color, given that naturals are very difficult to come by. Anyway, best of luck lemanmis and keep us posted!
            ______Perlas
            o-o-o E Unio Plurum o-o-o

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            • #21
              To the average person, they look random and dissimilar which gives rise to suspecting natural origin. However, to a trained eye, these appear to be the graded to the same luster, color and shape. If this stand were natural, grading around those three points would make for stunning, valuable strand.

              This is not that strand. The first problem is pearl length. These are drilled on the narrowest plane which suggests mass production. The pearls are drilled for speed and efficiency and volume. Drilling lengthwise is a slower, tedious process and risks shattering pearls. A natural strand will usually have pearls drilled by length and will be graded and regraded time and time again until it has the perfect match suited for their visual effect. This strand looks like someone had a bag of pearls and a string, placing the next pearl without much thought.

              The absence of a bead does not mean they have no nucleus. All pearls have a nucleus, but some natural pearls have no visible nucleus (albeit microscopic). Grafted tissue in cultured pearls always leaves a signature. A signature that is nearly identical to the rest of the pearls in the lot. Natural pearls will have markedly different nuclei. For that reason, I'd examine candled views, but be forewarned that drilled pearls are destroyed pearls from a scientific standpoint because much of the nuclear material is missing.

              Freshwater pearls are graded into lots and sold by the sack. These are potato pearls. As far as potato pearls go, they are nice potato pearls. They were high graded to avoid circular ridges and other shape imperfections seen on other potato grades, but there are visible lines in the nacre itself. Any "circling" is typical of fast growth from cultural techniques. Circling observed in single natural pearls usually imply two or more nuclei are present.

              lemanmls, I appreciate your concerns and accept your provenance at face value. However, the reputation of a pearl dealer does not suggest origin unless you have irrefutable evidence they were sourced from a natural pearler. Neither does age. Pearl culture has been going on for more than a century. Likewise, these do not look like fakes or anything other than what they were intended to be. Sometimes unscrupulous dealers will make intentional mismatches to give the appearance of being natural, but this strand does not present this way.

              I use a scoring system to determine whether a strand should go top the lab or not. I apply a potential score of 10. Although not a firm standard, a score of 5 would merit a trip to the lab based upon a balanced speculation. These scored low. Giving this strand all benefit of doubt, it's 9 to 1 cultural origin. Of course, you may challenge my opinion by sending it to a lab, but please realize you may diminish their current value to near zero.

              Natural vs CFWP

              Luster ---------- 0.5 - 0.5 Consistent with either.
              Shape ---------- 0.0 - 1.0 Graded match more common in CFWP.
              Inclusions ----- 0.0 - 1.0 No visible inclusions other than circular growth fronts.
              Matching ------ 0.0 - 1.0 Equal matches are possible, but drilling more consistent with mass production.
              Structure ------ 0.5 - 0.5 Known to be terraced aragonite, consistent with either.
              Size ------------ 0.0 - 1.0 Consistent with either but matched grade suggests cultural origin.
              Color ----------- 0.0 - 1.0 Uniform and consistent with CFWP.
              Translucency -- 0.0 - 1.0 Uniform and consistent with CFWP.
              Onset----------- 0.0 - 1.0 100% perisostracial growth, consistent with CFWP.
              Nuclear -------- 0.0 - 1.0 More uniform than not. No shell beads present.

              Natural - 1
              CFWP - 9

              This is a very nice strand. It's a very good example of something I expect we'll see more of in the future. A classic production version of an early, quality strand from China.

              Thank you for sharing it with us.

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              • #22
                Was on the phone with mum today. Mon Dieu!!! I had to hang up three times. She is willing to send all her jewellery she bought from the jewellery maker to gem lab. I should not have been involved in this. I big time regret. However, everything for a reason. I started to educate myself more on this subject and planning to take a specilization course for appraisal especially in antique jewellery in Germany . I am from fashion, have quite knowledge about costume history but definitely fond of antique & jewellery . Meantime, here are the x-rays. It was for this institute 1st time they had a jewellery in their lab taken x-ray

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                • #23
                  They wrote down that it is the first time they x-rayed a jewellery and they usually deal with metals and do not have knowledge on this subject. They said they can tomography them or micro spectroscopy. They will send me pictures from the lab to my phone and I am quite curious about it.

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                  • #24
                    lemanmls - It may just be me but I do not see any X-ray images? Please try adding them again. Thank you.

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                    • #25
                      Sorry everyone. I realized that they are in tiff . I converted them to jpg now. They also included that they gave different effects via filtration.

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                      • #26
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                        • #27
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                          • #28
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                            • #29
                              Originally posted by lemanmls View Post
                              [ATTACH]40557[/ATTACH] [ATTACH]40564[/ATTACH]
                              80% of the contrasts are identical. A profile of the tissue graft is clearly visible, equal in length and axis. The remaining 20% are identical, but eccentric patches.

                              These are cultured freshwater pearls.

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                              • #30
                                Really wonderful to see the x-rays, thank you for sharing!
                                http://www.oceanscovejewelry.com
                                Instagram: Ocean's Cove

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