Cracking pearls

[Pearling Technologies]

I'm not sure I agree with the same material theory. A lot of alternative nuclei have been used with varying degrees of success. Not so much regarding nacre formation but more so for workability by processors.

I would say that 99% of all nuclei used in Australia are ex mussel shell. Not necessarily ex USA but mussel shell.

[Josh]

What you mean by that is people are using Chinese mussel right?
Wait a minute.
Some where on this board I saw what looked like huge wasteful piles of Chinese oysters after harvest. Can anyone tell me if the shells of Chinese freshwater pearls are milled into nuclei? I ask this because we recently received more ("Pinctada") MOP beads that looked different than what we usually get, whiter and a little less regular but with classic top and bottom shine spots that characterize real Pinctada MOP nuclei. We inspected them closely and they were clean with a nice finish. They also drilled like dream. Could these nuclei be freshwater MOP and not saltwater? There's maybe one person on this whole forum who can answer this, I hope.

[jshepherd]

Yes, they can be used for nuclei. But the shells are too thin for anything larger than 6-7 mm, so unless you received a batch of small beads, it did not come from the Hyriopsis cumingii. The shell is mainly used for crafts, buttons, and of course all those products that have "pearl powder".

[Josh]

I had a hunch who that one person was.
Then the new nucs could only be P. Maxima right? The nuclei were around 10mm in diameter(3.3bu).

[Pearling Technologies]

From all the MOP processing we have done we have seen quite a variation in colour. From darker tan to quite light, as you have experienced. Of course there is the issue of bleaching although i would doubt that this would be necessary or worth considering for the MOP.

Some of the shells i have seen in China have tended to be on the thinner side but still with good capacity to produce beads or reaonsble size but mainly small.

Certainly Chinese mussel is being used for mainstream production. A lot of the shell has a certain opaqueness to it rather than pure and bright clean colouring of US shells but characteristics required as a nucleus material are similar to US shells.

[Valeria101]

Yes, they can be used for nuclei. But the shells are too thin for anything larger than 6-7 mm...

Is the use of small nuclei the reason why many of the nucleated freshwaters come with such thick nacre and such odd shapes?

[jshepherd]

Is the use of small nuclei the reason why many of the nucleated freshwaters come with such thick nacre and such odd shapes?

I don't believe so. The beads I have seen in CBSB have all been very large, 9 mm and above. Strictly based on economics there really is no other shell that could be used than the Tridacna gigas. The shapes are due to the pearl sac elasticity. The pearl sacs in second grafting of freshwater are not like those in saltwater. They are in the mantle muscle, not the gonad. It is much more difficult to slip a bead into a perfect pocket when it is in the mantle. The sac changes shape and the epithelial cells continue nacre deposition.

[Josh]

Jeremy,
Do you or anyone else know if there are any youtube vids on "in the mantle grafting" of Chinese fresh water's? Mrs. Strack went over it in her lecture in Tucson but it would be good to have something to watch a few times.

[jshepherd]

This one http://www.youtube.com/watch?v=8uXeSb7i5X0. If you need a close up in higher resolution let me know. YouTube is a little blurry.

[Josh]

You can't see what is going on at all inside the critter but the speed of the "incision" makes me think they are just stuffing mantle tissue pieces under the host oysters mantle. Either that or more probably, the mantle is nothing like P. Margaritifera and the technology is totally nontransferable.

[JWei]

Some farmers in China are trying to use similar methods used in SSP.
I have asked one bead manufacture why he does not use the shells of saltwater oysters. They told me that those beads are not densely enough and easily to be broken up.
Josh, Is the shell of saltwater oysters not solid?

[CortezPearls]

The Freshwater technique involves a "mantle within mantle" procedure. That is: you make a little "taco" (or "quesadilla" if you prefer) of mantle tissue and you insert it within the mantle of the mussel.

You cannot graft saltwater oysters (Pteriidae) using this method, because the mantle of the pearly mussels is much thicker than that of the pearl oysters. We tried this technique many years ago...not much success there.

[CortezPearls]

Some farmers in China are trying to use similar methods used in SSP.
I have asked one bead manufacture why he does not use the shells of saltwater oysters. They told me that those beads are not densely enough and easily to be broken up.
Josh, Is the shell of saltwater oysters not solid?

The shell is solid...but either not thick enough to produce large nuclei or its thermal expansion coefficient is not close enough to that of nacre...thus pearls might explode when drilled.

[CortezPearls]

Yes, they can be used for nuclei. But the shells are too thin for anything larger than 6-7 mm, so unless you received a batch of small beads, it did not come from the Hyriopsis cumingii. The shell is mainly used for crafts, buttons, and of course all those products that have "pearl powder".

Mr. Shigeru Akamatsu had some nuclei that he was showing in Tucson. These were "reconstituted nuclei" (to give them a name): chinese mussel shells that had been glued toghether and then processed. The resulting nucleus was 16 mm in diameter, but you could see where the different shells were glued (due to the transparency of the glue AND the way the bands/lines met).

We would never buy nuclei like these...but if they are being manufactured, then it means someone is using them.

[Slraep]

Mr. Shigeru Akamatsu had some nuclei that he was showing in Tucson. These were "reconstituted nuclei" (to give them a name): chinese mussel shells that had been glued toghether and then processed. The resulting nucleus was 16 mm in diameter, but you could see where the different shells were glued (due to the transparency of the glue AND the way the bands/lines met).

We would never buy nuclei like these...but if they are being manufactured, then it means someone is using them.

Hola Douglas,

Those composite nuclei have been around for a little while. Some of them are B_I_G. No one wants to admit to using them. They are being sold! I suspect Philipine farmers of SSs, but who knows. I posted a company from Denmark that sells them.

Check out this thread:

Size of nucleus

http://www.pearl-guide.com/forum/sho...mposite+nuclei

Slraep