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Little festoon necklace, natural pearls?

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  • #16
    Your pearls do look like some of my small natural Persian Gulf pearls. So far your nuclei are quite variable so that bodes well for natural, (yes, Dave?). It looks like a restringing may have replaced a few pearls- but candling should tell that story. Take your time, but candle them all. For one thing you will get to know each pearl from the outside when you candle. I recognize almost every natural pearl I have as being one I know personally, and would probably recognize out of context.

    In any case, you've got a beaut!.

    Dave, that was a good insight about the variability of causes in initiating natural pearls -and the single cause of cultured! as well as how they vary inside from each other, and from the signature look of a grafted freshwater. Its part of my vocabulary now.
    Caitlin

    How to hand-knot pearls without a tool

    My avatar is a Sea of Cortez mabe pearl. One of a pair of Mexican handmade earrings.

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    • #17
      Kyratango, your festoon necklace of pearls is lovely ... these pearls have a gorgeous luster and luminosity
      Cathy

      CathyKeshi

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      • #18
        Originally posted by Caitlin View Post
        ... so that bodes well for natural, (yes, Dave?)
        Natural vs CFWP

        Luster ----------- 0.5 - 0.5 Consistent with either
        Shape ----------- 0.0 - 1.0 More common in CFWP, numerous flat spots.
        Inclusions ------ 0.0 - 1.0 Does not present with inclusions.
        Matching ------- 0.5 - 0.5 Equal matches are possible, but more consistent with CFWP.
        Structure ------- 0.5 - 0.5 Known to be terraced aragonite, consistent with either
        Size -------------- 0.5 - 0.5 Consistent with either
        Color ------------ 0.5 - 0.5 Consistent with either
        Translucency --- 0.5 - 0.5 Consistent with either
        Onset ----------- 0.0 - 0.0 Unknown at this time. No point scored (Even though imagery supports periostracial origin)
        Nuclear --------- 0.0 - 1.0 More uniform than not. No shell beads present.

        Natural - 3
        CFWP - 6

        A better look at the nuclei could raise this score to 5 or 5.5 which is only half way there. At the very least, a score of 5 or more merits a trip to the lab.

        Of the current images, only one has enough resolution (from only a single axis) and appears consistent with a tissue graft.

        In the meantime, anyone who owns a FW strand can see for themselves. Hold them to a lamp and look at every pearl. Even thought they'll never be perfectly identical. you'll see similarities. Likewise Caitlin, you have some naturals... try the same with those. I'm certain you'll see differences.

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        • #19
          Originally posted by Caitlin View Post
          Dave, that was a good insight about the variability of causes in initiating natural pearls -and the single cause of cultured! as well as how they vary inside from each other, and from the signature look of a grafted freshwater. Its part of my vocabulary now.

          Mantle tissue is used to perform the graft of identical species. Hence the onset can be deemed as "periostracial" and "homogeneic" in origin. This is because the grafted tissue is already performing active mineralization from at least one side of the epithelium.

          Only a medium percentage of naturals are periostracial, but almost never homogeneic (other than by it's own tissues or extreme fluke). Afterall, there's no graft donor. Parasites causing lesions may be septic and periostracial in many cases, but are considered xenogeneic in origin.

          Naturals may also be formed by myostracial, byssal or visceral onset. The myostracum of bivalves is a fancy word for connective membranes. It holds all of the organs together, surrounds the adductor muscles and fastens them to the shell. Normally they do no mineralize structures, BUT with some intervention, stresses, injury or growth they'll become so.

          A good example for myostracial origin are abalone horns. After all, what is normally soft tissue otherwise became mineralized. Pearls from perforations in abalone are periostracial in origin, because they form in the mantle. Myostracial pearls rarely have any visible nucleus.

          Pearls may also form in the byssal glands or in the guts which could be either, depending on the stress (whether sterile or septic). Byssal lesions are generally aseptic and myostracial from strains, but if a bug gets in there it's septic and either.

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          • #20
            Thanks Caitlin and Dave !
            Candling is exhausting... They seem to me to be beryl translucide, I can't see differences between them, impossible to get focus on such tiny things :-/
            Dave, your writing is very interesting, will keep it in doc Base :-)

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